diff --git a/core/authorize.php b/core/authorize.php
index ae536285c7c97b0942514c87b34947abc86dac0d..ecb7e22a4347f42a793eeb338d8e318c1fb30822 100644
--- a/core/authorize.php
+++ b/core/authorize.php
@@ -74,7 +74,7 @@ function authorize_access_allowed() {
 drupal_bootstrap(DRUPAL_BOOTSTRAP_VARIABLES);
 
 $request = Request::createFromGlobals();
-Drupal::getContainer()->set('request', $request);
+\Drupal::getContainer()->set('request', $request);
 
 // This must go after drupal_bootstrap(), which unsets globals!
 global $conf;
@@ -83,9 +83,9 @@ function authorize_access_allowed() {
 // display errors via the maintenance theme.
 $module_list['system'] = 'core/modules/system/system.module';
 $module_list['user'] = 'core/modules/user/user.module';
-Drupal::moduleHandler()->setModuleList($module_list);
-Drupal::moduleHandler()->load('system');
-Drupal::moduleHandler()->load('user');
+\Drupal::moduleHandler()->setModuleList($module_list);
+\Drupal::moduleHandler()->load('system');
+\Drupal::moduleHandler()->load('user');
 
 // Initialize the language system.
 drupal_language_initialize();
diff --git a/core/includes/ajax.inc b/core/includes/ajax.inc
index ac1d4cbc869f9c9bd232c7ba03dc66ee16f85abd..bb777988df678412a76bf5d9da8140fd5b999160 100644
--- a/core/includes/ajax.inc
+++ b/core/includes/ajax.inc
@@ -332,7 +332,7 @@ function ajax_base_page_theme() {
     // to see the default theme, token validation isn't required for that, and
     // bypassing it allows most use-cases to work even when accessed from the
     // page cache.
-    if ($theme === Drupal::config('system.theme')->get('default') || drupal_valid_token($token, $theme)) {
+    if ($theme === \Drupal::config('system.theme')->get('default') || drupal_valid_token($token, $theme)) {
       return $theme;
     }
   }
@@ -368,7 +368,7 @@ function ajax_prepare_response($page_callback_result) {
         break;
 
       case MENU_SITE_OFFLINE:
-        $commands[] = ajax_command_alert(filter_xss_admin(t(Drupal::config('system.maintenance')->get('message'), array('@site' => Drupal::config('system.site')->get('name')))));
+        $commands[] = ajax_command_alert(filter_xss_admin(t(\Drupal::config('system.maintenance')->get('message'), array('@site' => \Drupal::config('system.site')->get('name')))));
         break;
     }
   }
diff --git a/core/includes/authorize.inc b/core/includes/authorize.inc
index 8b6ef01c3ea34afbccb2ff891cc5befe41e17bb5..481fd300df20f3576b145d96c2ebf538b71e0af3 100644
--- a/core/includes/authorize.inc
+++ b/core/includes/authorize.inc
@@ -27,7 +27,7 @@ function authorize_filetransfer_form($form, &$form_state) {
   }
   $available_backends = $_SESSION['authorize_filetransfer_info'];
 
-  if (!Drupal::request()->isSecure()) {
+  if (!\Drupal::request()->isSecure()) {
     $form['information']['https_warning'] = array(
       '#prefix' => '<div class="messages messages--error">',
       '#markup' => t('WARNING: You are not using an encrypted connection, so your password will be sent in plain text. <a href="@https-link">Learn more</a>.', array('@https-link' => 'http://drupal.org/https-information')),
@@ -39,7 +39,7 @@ function authorize_filetransfer_form($form, &$form_state) {
   if (isset($form_state['values']['connection_settings']['authorize_filetransfer_default'])) {
     $authorize_filetransfer_default = $form_state['values']['connection_settings']['authorize_filetransfer_default'];
   }
-  elseif ($authorize_filetransfer_default = Drupal::config('system.authorize')->get('filetransfer_default'));
+  elseif ($authorize_filetransfer_default = \Drupal::config('system.authorize')->get('filetransfer_default'));
   else {
     $authorize_filetransfer_default = key($available_backends);
   }
@@ -138,7 +138,7 @@ function authorize_filetransfer_form($form, &$form_state) {
  * @see hook_filetransfer_backends()
  */
 function _authorize_filetransfer_connection_settings($backend) {
-  $auth_connection_config = Drupal::config('system.authorize')->get('filetransfer_connection_settings_' . $backend);
+  $auth_connection_config = \Drupal::config('system.authorize')->get('filetransfer_connection_settings_' . $backend);
   $defaults = $auth_connection_config ? $auth_connection_config : array();
   $form = array();
 
@@ -253,9 +253,9 @@ function authorize_filetransfer_form_submit($form, &$form_state) {
           }
         }
         // Set this one as the default authorize method.
-        Drupal::config('system.authorize')->set('filetransfer_default', $filetransfer_backend);
+        \Drupal::config('system.authorize')->set('filetransfer_default', $filetransfer_backend);
         // Save the connection settings minus the password.
-        Drupal::config('system.authorize')->set('filetransfer_connection_settings_' . $filetransfer_backend, $connection_settings);
+        \Drupal::config('system.authorize')->set('filetransfer_connection_settings_' . $filetransfer_backend, $connection_settings);
 
         $filetransfer = authorize_get_filetransfer($filetransfer_backend, $form_state['values']['connection_settings'][$filetransfer_backend]);
 
diff --git a/core/includes/batch.inc b/core/includes/batch.inc
index 889799c496ef385ff845cb207f58d3b1d79660cc..14f4499c658be2183521d8f5471daac6c2f8b8f4 100644
--- a/core/includes/batch.inc
+++ b/core/includes/batch.inc
@@ -36,7 +36,7 @@ function _batch_page(Request $request) {
 
   // Retrieve the current state of the batch.
   if (!$batch) {
-    $batch = Drupal::service('batch.storage')->load($request_id);
+    $batch = \Drupal::service('batch.storage')->load($request_id);
     if (!$batch) {
       drupal_set_message(t('No active batch.'), 'error');
       return new RedirectResponse(url('<front>', array('absolute' => TRUE)));
@@ -394,7 +394,7 @@ function _batch_finished() {
 
   // Clean up the batch table and unset the static $batch variable.
   if ($batch['progressive']) {
-    Drupal::service('batch.storage')->delete($batch['id']);
+    \Drupal::service('batch.storage')->delete($batch['id']);
     foreach ($batch['sets'] as $batch_set) {
       if ($queue = _batch_queue($batch_set)) {
         $queue->deleteQueue();
@@ -415,7 +415,7 @@ function _batch_finished() {
   if ($_batch['progressive']) {
     // Revert the 'destination' that was saved in batch_process().
     if (isset($_batch['destination'])) {
-      Drupal::request()->query->set('destination', $_batch['destination']);
+      \Drupal::request()->query->set('destination', $_batch['destination']);
     }
 
     // Determine the target path to redirect to.
@@ -463,6 +463,6 @@ function _batch_finished() {
  */
 function _batch_shutdown() {
   if ($batch = batch_get()) {
-    Drupal::service('batch.storage')->update($batch);
+    \Drupal::service('batch.storage')->update($batch);
   }
 }
diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index e8350cf0a3a87bd3e04434707701cede86395885..32f47fa1d8e5e2307656cbf3a89a2b781ae879c1 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -451,7 +451,7 @@ function config_get_config_directory($type = CONFIG_ACTIVE_DIRECTORY) {
  * return the expected values.
  *
  * Most other parameters do not need to be passed in, but may be necessary in
- * some cases; for example, if Drupal::request()->getClientIP()
+ * some cases; for example, if \Drupal::request()->getClientIP()
  * needs to return anything but the standard localhost value ('127.0.0.1'),
  * the command line script should pass in the desired value via the
  * 'REMOTE_ADDR' key.
@@ -744,17 +744,17 @@ function drupal_get_filename($type, $name, $filename = NULL) {
     // Verify that we have an keyvalue service before using it. This is required
     // because this function is called during installation.
     // @todo Inject database connection into KeyValueStore\DatabaseStorage.
-    if (($container = Drupal::getContainer()) && $container->has('keyvalue') && function_exists('db_query')) {
+    if (($container = \Drupal::getContainer()) && $container->has('keyvalue') && function_exists('db_query')) {
       if ($type == 'module') {
         if (empty($files[$type])) {
-          $files[$type] = Drupal::moduleHandler()->getModuleList();
+          $files[$type] = \Drupal::moduleHandler()->getModuleList();
         }
         if (isset($files[$type][$name])) {
           return $files[$type][$name];
         }
       }
       try {
-        $file_list = Drupal::state()->get('system.' . $type . '.files');
+        $file_list = \Drupal::state()->get('system.' . $type . '.files');
         if ($file_list && isset($file_list[$name]) && file_exists(DRUPAL_ROOT . '/' . $file_list[$name])) {
           $files[$type][$name] = $file_list[$name];
         }
@@ -839,7 +839,7 @@ function variable_initialize($conf = array()) {
   else {
     // Cache miss. Avoid a stampede.
     $name = 'variable_init';
-    $lock = Drupal::lock();
+    $lock = \Drupal::lock();
     if (!$lock->acquire($name, 1)) {
       // Another request is building the variable cache.
       // Wait, then re-run this function.
@@ -953,7 +953,7 @@ function variable_del($name) {
 function drupal_page_cache_get_cid(Request $request) {
   $cid_parts = array(
     $request->getUri(),
-    Drupal::service('content_negotiation')->getContentType($request),
+    \Drupal::service('content_negotiation')->getContentType($request),
   );
   return sha1(implode(':', $cid_parts));
 }
@@ -974,7 +974,7 @@ function drupal_page_cache_get_cid(Request $request) {
  */
 function drupal_page_get_cache(Request $request) {
   if (drupal_page_is_cacheable()) {
-    return Drupal::cache('page')->get(drupal_page_cache_get_cid($request));
+    return \Drupal::cache('page')->get(drupal_page_cache_get_cid($request));
   }
 }
 
@@ -1011,8 +1011,8 @@ function drupal_page_is_cacheable($allow_caching = NULL) {
  *   TRUE if the item is loaded or has already been loaded.
  */
 function drupal_load($type, $name) {
-  if ($type == 'module' && Drupal::moduleHandler()->moduleExists($name)) {
-    return Drupal::moduleHandler()->load($name);
+  if ($type == 'module' && \Drupal::moduleHandler()->moduleExists($name)) {
+    return \Drupal::moduleHandler()->load($name);
   }
 
   // Once a file is included this can't be reversed during a request so do not
@@ -1211,7 +1211,7 @@ function drupal_page_header() {
  * response is sent.
  */
 function drupal_serve_page_from_cache(stdClass $cache, Response $response, Request $request) {
-  $config = Drupal::config('system.performance');
+  $config = \Drupal::config('system.performance');
 
   // First half: we must determine if we should be returning a 304.
 
@@ -1354,7 +1354,7 @@ function drupal_serve_page_from_cache(stdClass $cache, Response $response, Reque
  * @ingroup sanitization
  */
 function t($string, array $args = array(), array $options = array()) {
-  return Drupal::translation()->translate($string, $args, $options);
+  return \Drupal::translation()->translate($string, $args, $options);
 }
 
 /**
@@ -1542,7 +1542,7 @@ function watchdog($type, $message, array $variables = NULL, $severity = WATCHDOG
     );
 
     try {
-      $request = Drupal::request();
+      $request = \Drupal::request();
       $log_entry['request_uri'] = $request->getUri();
       $log_entry['referer'] = $request->headers->get('Referer', '');
       $log_entry['ip'] = $request->getClientIP();
@@ -1552,7 +1552,7 @@ function watchdog($type, $message, array $variables = NULL, $severity = WATCHDOG
     }
 
     // Call the logging hooks to log/process the message
-    foreach (Drupal::moduleHandler()->getImplementations('watchdog') as $module) {
+    foreach (\Drupal::moduleHandler()->getImplementations('watchdog') as $module) {
       $function = $module . '_watchdog';
       $function($log_entry);
     }
@@ -1714,7 +1714,7 @@ function drupal_set_title($title = NULL, $output = Title::CHECK_PLAIN) {
 function drupal_anonymous_user() {
   $values = array(
     'uid' => 0,
-    'hostname' => Drupal::request()->getClientIP(),
+    'hostname' => \Drupal::request()->getClientIP(),
     'roles' => array(DRUPAL_ANONYMOUS_RID),
   );
   return new UserSession($values);
@@ -1869,7 +1869,7 @@ function drupal_handle_request($test_only = FALSE) {
  */
 function drupal_get_user_timezone() {
   global $user;
-  $config = Drupal::config('system.date');
+  $config = \Drupal::config('system.date');
 
   if ($user && $config->get('timezone.user.configurable') && $user->isAuthenticated() && $user->getTimezone()) {
     return $user->getTimezone();
@@ -1966,7 +1966,7 @@ function _drupal_bootstrap_configuration() {
   // Load the procedural configuration system helper functions.
   require_once __DIR__ . '/config.inc';
 
-  // Set the Drupal custom error handler. (requires Drupal::config())
+  // Set the Drupal custom error handler. (requires \Drupal::config())
   set_error_handler('_drupal_error_handler');
   set_exception_handler('_drupal_exception_handler');
 
@@ -1985,7 +1985,7 @@ function _drupal_bootstrap_configuration() {
 function _drupal_bootstrap_kernel() {
   // Normally, index.php puts a container in the Drupal class by creating a
   // kernel. If there is no container yet, create one.
-  if (!Drupal::getContainer()) {
+  if (!\Drupal::getContainer()) {
     $kernel = new DrupalKernel('prod', drupal_classloader());
     $kernel->boot();
   }
@@ -2004,7 +2004,7 @@ function _drupal_bootstrap_page_cache() {
   }
   else {
     drupal_bootstrap(DRUPAL_BOOTSTRAP_VARIABLES, FALSE);
-    $config = Drupal::config('system.performance');
+    $config = \Drupal::config('system.performance');
     $cache_enabled = $config->get('cache.page.use_internal');
   }
 
@@ -2112,19 +2112,19 @@ function drupal_get_bootstrap_phase() {
  *   object instances or FALSE if none exist yet.
  */
 function drupal_container() {
-  return Drupal::getContainer();
+  return \Drupal::getContainer();
 }
 
 /**
  * Returns the list of enabled modules.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->getModuleList().
+ *   \Drupal::moduleHandler()->getModuleList().
  *
  * @see \Drupal\Core\Extension\ModuleHandler::getModuleList()
  */
 function module_list() {
-  $modules = array_keys(Drupal::moduleHandler()->getModuleList());
+  $modules = array_keys(\Drupal::moduleHandler()->getModuleList());
   return array_combine($modules, $modules);
 }
 
@@ -2132,12 +2132,12 @@ function module_list() {
  * Determines which modules are implementing a hook.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->getImplementations($hook).
+ *   \Drupal::moduleHandler()->getImplementations($hook).
  *
  * @see \Drupal\Core\Extension\ModuleHandler::getImplementations()
  */
 function module_implements($hook) {
-  return Drupal::moduleHandler()->getImplementations($hook);
+  return \Drupal::moduleHandler()->getImplementations($hook);
 }
 
 /**
@@ -2147,7 +2147,7 @@ function module_implements($hook) {
  * arguments by reference.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->invoke($module, $hook, $args = array()).
+ *   \Drupal::moduleHandler()->invoke($module, $hook, $args = array()).
  *
  * @see drupal_alter()
  * @see \Drupal\Core\Extension\ModuleHandler::invoke()
@@ -2156,7 +2156,7 @@ function module_invoke($module, $hook) {
   $args = func_get_args();
   // Remove $module and $hook from the arguments.
   unset($args[0], $args[1]);
-  return Drupal::moduleHandler()->invoke($module, $hook, $args);
+  return \Drupal::moduleHandler()->invoke($module, $hook, $args);
 }
 
 /**
@@ -2166,7 +2166,7 @@ function module_invoke($module, $hook) {
  * arguments by reference.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->invokeAll($hook).
+ *   \Drupal::moduleHandler()->invokeAll($hook).
  *
  * @see drupal_alter()
  * @see \Drupal\Core\Extension\ModuleHandler::invokeAll()
@@ -2175,43 +2175,43 @@ function module_invoke_all($hook) {
   $args = func_get_args();
   // Remove $hook from the arguments.
   array_shift($args);
-  return Drupal::moduleHandler()->invokeAll($hook, $args);
+  return \Drupal::moduleHandler()->invokeAll($hook, $args);
 }
 
 /**
  * Passes alterable variables to specific hook_TYPE_alter() implementations.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->alter($hook).
+ *   \Drupal::moduleHandler()->alter($hook).
  *
  * @see \Drupal\Core\Extension\ModuleHandler::alter()
  */
 function drupal_alter($type, &$data, &$context1 = NULL, &$context2 = NULL) {
-  return Drupal::moduleHandler()->alter($type, $data, $context1, $context2);
+  return \Drupal::moduleHandler()->alter($type, $data, $context1, $context2);
 }
 
 /**
  * Determines whether a given module exists.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->moduleExists($module).
+ *   \Drupal::moduleHandler()->moduleExists($module).
  *
  * @see \Drupal\Core\Extension\ModuleHandler::moduleExists()
  */
 function module_exists($module) {
-  return Drupal::moduleHandler()->moduleExists($module);
+  return \Drupal::moduleHandler()->moduleExists($module);
 }
 
 /**
  * Determines whether a module implements a hook.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->implementsHook($module, $hook).
+ *   \Drupal::moduleHandler()->implementsHook($module, $hook).
  *
  * @see \Drupal\Core\Extension\ModuleHandler::implementsHook()
  */
 function module_hook($module, $hook) {
-  return Drupal::moduleHandler()->implementsHook($module, $hook);
+  return \Drupal::moduleHandler()->implementsHook($module, $hook);
 }
 
 /**
@@ -2345,9 +2345,9 @@ function drupal_installation_attempted() {
  * Initializes all the defined language types and sets the default langcode.
  */
 function drupal_language_initialize() {
-  $language_manager = Drupal::languageManager();
+  $language_manager = \Drupal::languageManager();
   $language_manager->init();
-  Drupal::translation()->setDefaultLangcode($language_manager->getLanguage(Language::TYPE_INTERFACE)->id);
+  \Drupal::translation()->setDefaultLangcode($language_manager->getLanguage(Language::TYPE_INTERFACE)->id);
 }
 
 /**
@@ -2359,10 +2359,10 @@ function drupal_language_initialize() {
  *   The type of language object needed, e.g. Language::TYPE_INTERFACE.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::languageManager()->getLanguage($type).
+ *   \Drupal::languageManager()->getLanguage($type).
  */
 function language($type) {
-  return Drupal::languageManager()->getLanguage($type);
+  return \Drupal::languageManager()->getLanguage($type);
 }
 
 /**
@@ -2373,7 +2373,7 @@ function language($type) {
  *   name and its value is its configurability (TRUE/FALSE).
  */
 function language_types_get_all() {
-  $types = Drupal::config('system.language.types')->get('all');
+  $types = \Drupal::config('system.language.types')->get('all');
   return $types ? $types : array_keys(language_types_get_default());
 }
 
@@ -2399,7 +2399,7 @@ function language_types_get_default() {
  *   TRUE if more than one language is enabled.
  */
 function language_multilingual() {
-  return Drupal::languageManager()->isMultilingual();
+  return \Drupal::languageManager()->isMultilingual();
 }
 
 /**
@@ -2433,7 +2433,7 @@ function language_list($flags = Language::STATE_CONFIGURABLE) {
       // save the same object without data loss.
       foreach ($language_entities as $langcode_config_name) {
         $langcode = substr($langcode_config_name, strlen('language.entity.'));
-        $info = Drupal::config($langcode_config_name)->get();
+        $info = \Drupal::config($langcode_config_name)->get();
         $languages[$langcode] = new Language(array(
           'default' => ($info['id'] == $default->id),
           'name' => $info['label'],
@@ -3083,13 +3083,13 @@ function drupal_check_memory_limit($required, $memory_limit = NULL) {
 /**
  * Get locking layer instance.
  *
- * @deprecated Use Drupal::lock() instead, or even better have the lock service
+ * @deprecated Use \Drupal::lock() instead, or even better have the lock service
  *   injected into your object.
  *
  * @return Drupal\Core\Lock\LockBackendInterface
  */
 function lock() {
-  return Drupal::lock();
+  return \Drupal::lock();
 }
 
 /**
diff --git a/core/includes/cache.inc b/core/includes/cache.inc
index edc47c76b44fe356579ff7765d3620eddf188a5a..d7dca8e310243ed28add7cc6a099712dbfee793a 100644
--- a/core/includes/cache.inc
+++ b/core/includes/cache.inc
@@ -26,7 +26,7 @@
  * @see Drupal\Core\Cache\CacheBackendInterface
  */
 function cache($bin = 'cache') {
-  return Drupal::cache($bin);
+  return \Drupal::cache($bin);
 }
 
 /**
diff --git a/core/includes/common.inc b/core/includes/common.inc
index 94eac7dae9f3e9a1c17d084cc31a305fbf2bd1c9..be97724479fea2257bea7f51bd883c2011aa0a07 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -361,7 +361,7 @@ function _drupal_default_html_head() {
   );
   // Show Drupal and the major version number in the META GENERATOR tag.
   // Get the major version.
-  list($version, ) = explode('.', Drupal::VERSION);
+  list($version, ) = explode('.', \Drupal::VERSION);
   $elements['system_meta_generator'] = array(
     '#type' => 'html_tag',
     '#tag' => 'meta',
@@ -447,7 +447,7 @@ function drupal_get_feeds($delimiter = "\n") {
  */
 function drupal_get_query_parameters(array $query = NULL, array $exclude = array(), $parent = '') {
   if (!isset($query)) {
-    $query = Drupal::request()->query->all();
+    $query = \Drupal::request()->query->all();
   }
   return Url::filterQueryParameters($query, $exclude, $parent);
 }
@@ -487,7 +487,7 @@ function drupal_get_destination() {
     return $destination;
   }
 
-  $query = Drupal::request()->query;
+  $query = \Drupal::request()->query;
   if ($query->has('destination')) {
     $destination = array('destination' => $query->get('destination'));
   }
@@ -1110,7 +1110,7 @@ function format_interval($interval, $granularity = 2, $langcode = NULL) {
  * @see \Drupal\Component\Datetime\Date::format()
  */
 function format_date($timestamp, $type = 'medium', $format = '', $timezone = NULL, $langcode = NULL) {
-  return Drupal::service('date')->format($timestamp, $type, $format, $timezone, $langcode);
+  return \Drupal::service('date')->format($timestamp, $type, $format, $timezone, $langcode);
 }
 
 /**
@@ -1201,7 +1201,7 @@ function datetime_default_format_type() {
  * @see \Drupal\Core\Routing\UrlGeneratorInterface::generateFromPath().
  */
 function url($path = NULL, array $options = array()) {
-  $generator = Drupal::urlGenerator();
+  $generator = \Drupal::urlGenerator();
   try {
     $url = $generator->generateFromPath($path, $options);
   }
@@ -1345,7 +1345,7 @@ function l($text, $path, array $options = array()) {
       'path' => current_path(),
       'front_page' => drupal_is_front_page(),
       'language' => language(Language::TYPE_URL)->id,
-      'query' => Drupal::service('request')->query->all(),
+      'query' => \Drupal::service('request')->query->all(),
     );
   }
 
@@ -1371,7 +1371,7 @@ function l($text, $path, array $options = array()) {
   }
 
   // Allow other modules to modify the structure of the link.
-  Drupal::moduleHandler()->alter('link', $variables);
+  \Drupal::moduleHandler()->alter('link', $variables);
 
   // Move attributes out of options. url() doesn't need them.
   $attributes = new Attribute($variables['options']['attributes']);
@@ -1861,7 +1861,7 @@ function drupal_pre_render_styles($elements) {
   $css_assets = $elements['#items'];
 
   // Aggregate the CSS if necessary, but only during normal site operation.
-  if (!defined('MAINTENANCE_MODE') && Drupal::config('system.performance')->get('css.preprocess')) {
+  if (!defined('MAINTENANCE_MODE') && \Drupal::config('system.performance')->get('css.preprocess')) {
     $css_assets = \Drupal::service('asset.css.collection_optimizer')->optimize($css_assets);
   }
   return \Drupal::service('asset.css.collection_renderer')->render($css_assets);
@@ -1871,7 +1871,7 @@ function drupal_pre_render_styles($elements) {
  * Deletes old cached CSS files.
  */
 function drupal_clear_css_cache() {
-  Drupal::state()->delete('drupal_css_cache_files');
+  \Drupal::state()->delete('drupal_css_cache_files');
   file_scan_directory('public://css', '/.*/', array('callback' => 'drupal_delete_file_if_stale'));
 }
 
@@ -1884,7 +1884,7 @@ function drupal_clear_css_cache() {
  */
 function drupal_delete_file_if_stale($uri) {
   // Default stale file threshold is 30 days.
-  if (REQUEST_TIME - filemtime($uri) > Drupal::config('system.performance')->get('stale_file_threshold')) {
+  if (REQUEST_TIME - filemtime($uri) > \Drupal::config('system.performance')->get('stale_file_threshold')) {
     file_unmanaged_delete($uri);
   }
 }
@@ -2488,7 +2488,7 @@ function drupal_pre_render_scripts($elements) {
 
   // Aggregate the JavaScript if necessary, but only during normal site
   // operation.
-  if (!defined('MAINTENANCE_MODE') && Drupal::config('system.performance')->get('js.preprocess')) {
+  if (!defined('MAINTENANCE_MODE') && \Drupal::config('system.performance')->get('js.preprocess')) {
     $js_assets = \Drupal::service('asset.js.collection_optimizer')->optimize($js_assets);
   }
   return \Drupal::service('asset.js.collection_renderer')->render($js_assets);
@@ -2999,8 +2999,8 @@ function drupal_add_tabledrag($table_id, $action, $relationship, $group, $subgro
  * Deletes old cached JavaScript files and variables.
  */
 function drupal_clear_js_cache() {
-  Drupal::state()->delete('system.javascript_parsed');
-  Drupal::state()->delete('system.js_cache_files');
+  \Drupal::state()->delete('system.javascript_parsed');
+  \Drupal::state()->delete('system.js_cache_files');
   file_scan_directory('public://js', '/.*/', array('callback' => 'drupal_delete_file_if_stale'));
 }
 
@@ -3106,7 +3106,7 @@ function _drupal_bootstrap_code() {
   require_once __DIR__ . '/entity.inc';
 
   // Load all enabled modules
-  Drupal::moduleHandler()->loadAll();
+  \Drupal::moduleHandler()->loadAll();
 
   // Make sure all stream wrappers are registered.
   file_get_stream_wrappers();
@@ -3120,7 +3120,7 @@ function _drupal_bootstrap_code() {
   }
 
   // Set the allowed protocols once we have the config available.
-  $allowed_protocols = Drupal::config('system.filter')->get('protocols');
+  $allowed_protocols = \Drupal::config('system.filter')->get('protocols');
   if (!isset($allowed_protocols)) {
     // filter_xss_admin() is called by the installer and update.php, in which
     // case the configuration may not exist (yet). Provide a minimal default set
@@ -3180,7 +3180,7 @@ function drupal_page_set_cache(Response $response, Request $request) {
   if (drupal_page_is_cacheable()) {
 
     // Check if the current page may be compressed.
-    $page_compressed = Drupal::config('system.performance')->get('response.gzip') && extension_loaded('zlib');
+    $page_compressed = \Drupal::config('system.performance')->get('response.gzip') && extension_loaded('zlib');
 
     $cache = (object) array(
       'cid' => drupal_page_cache_get_cid($request),
@@ -3248,7 +3248,7 @@ function drupal_cron_run() {
 
   $return = FALSE;
   // Grab the defined cron queues.
-  $queues = Drupal::moduleHandler()->invokeAll('queue_info');
+  $queues = \Drupal::moduleHandler()->invokeAll('queue_info');
   drupal_alter('queue_info', $queues);
 
   // Try to acquire cron lock.
@@ -3261,12 +3261,12 @@ function drupal_cron_run() {
     // existing queue.
     foreach ($queues as $queue_name => $info) {
       if (isset($info['cron'])) {
-        Drupal::queue($queue_name)->createQueue();
+        \Drupal::queue($queue_name)->createQueue();
       }
     }
 
     // Iterate through the modules calling their cron handlers (if any):
-    foreach (Drupal::moduleHandler()->getImplementations('cron') as $module) {
+    foreach (\Drupal::moduleHandler()->getImplementations('cron') as $module) {
       // Do not let an exception thrown by one module disturb another.
       try {
         module_invoke($module, 'cron');
@@ -3277,7 +3277,7 @@ function drupal_cron_run() {
     }
 
     // Record cron time.
-    Drupal::state()->set('system.cron_last', REQUEST_TIME);
+    \Drupal::state()->set('system.cron_last', REQUEST_TIME);
     watchdog('cron', 'Cron run completed.', array(), WATCHDOG_NOTICE);
 
     // Release cron lock.
@@ -3291,7 +3291,7 @@ function drupal_cron_run() {
     if (isset($info['cron'])) {
       $callback = $info['worker callback'];
       $end = time() + (isset($info['cron']['time']) ? $info['cron']['time'] : 15);
-      $queue = Drupal::queue($queue_name);
+      $queue = \Drupal::queue($queue_name);
       while (time() < $end && ($item = $queue->claimItem())) {
         call_user_func_array($callback, array($item->data));
         $queue->deleteItem($item);
@@ -3521,7 +3521,7 @@ function drupal_pre_render_link($element) {
 
   if (isset($element['#route_name'])) {
     $element['#route_parameters'] = empty($element['#route_parameters']) ? array() : $element['#route_parameters'];
-    $element['#markup'] = Drupal::linkGenerator()->generate($element['#title'], $element['#route_name'], $element['#route_parameters'], $element['#options']);
+    $element['#markup'] = \Drupal::linkGenerator()->generate($element['#title'], $element['#route_name'], $element['#route_parameters'], $element['#options']);
   }
   else {
     $element['#markup'] = l($element['#title'], $element['#href'], $element['#options']);
@@ -3671,7 +3671,7 @@ function drupal_render_page($page) {
   }
 
   // Modules can add elements to $page as needed in hook_page_build().
-  foreach (Drupal::moduleHandler()->getImplementations('page_build') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('page_build') as $module) {
     $function = $module . '_page_build';
     $function($page);
   }
@@ -4089,7 +4089,7 @@ function show(&$element) {
  * @see drupal_render_cache_set()
  */
 function drupal_render_cache_get($elements) {
-  if (!Drupal::request()->isMethodSafe() || !$cid = drupal_render_cid_create($elements)) {
+  if (!\Drupal::request()->isMethodSafe() || !$cid = drupal_render_cid_create($elements)) {
     return FALSE;
   }
   $bin = isset($elements['#cache']['bin']) ? $elements['#cache']['bin'] : 'cache';
@@ -4121,7 +4121,7 @@ function drupal_render_cache_get($elements) {
  */
 function drupal_render_cache_set(&$markup, $elements) {
   // Create the cache ID for the element.
-  if (!Drupal::request()->isMethodSafe() || !$cid = drupal_render_cid_create($elements)) {
+  if (!\Drupal::request()->isMethodSafe() || !$cid = drupal_render_cid_create($elements)) {
     return FALSE;
   }
 
@@ -4361,7 +4361,7 @@ function element_info($type) {
   $cache = &$drupal_static_fast['cache'];
 
   if (!isset($cache)) {
-    $cache = Drupal::moduleHandler()->invokeAll('element_info');
+    $cache = \Drupal::moduleHandler()->invokeAll('element_info');
     foreach ($cache as $element_type => $info) {
       $cache[$element_type]['#type'] = $element_type;
     }
@@ -4610,7 +4610,7 @@ function drupal_parse_info_file($filename) {
       $parser = new Parser();
       $info[$filename] = $parser->parse(file_get_contents($filename));
       if (isset($info[$filename]['version']) && $info[$filename]['version'] === 'VERSION') {
-        $info[$filename]['version'] = Drupal::VERSION;
+        $info[$filename]['version'] = \Drupal::VERSION;
       }
     }
   }
@@ -4720,7 +4720,7 @@ function drupal_implode_tags($tags) {
  *   requests.
  */
 function drupal_flush_all_caches() {
-  $module_handler = Drupal::moduleHandler();
+  $module_handler = \Drupal::moduleHandler();
   // Flush all persistent caches.
   // This is executed based on old/previously known information, which is
   // sufficient, since new extensions cannot have any primed caches yet.
@@ -4740,7 +4740,7 @@ function drupal_flush_all_caches() {
   drupal_static_reset();
 
   // Clear all non-drupal_static() static caches.
-  Drupal::entityManager()->clearCachedDefinitions();
+  \Drupal::entityManager()->clearCachedDefinitions();
 
   // Wipe the PHP Storage caches.
   PhpStorageFactory::get('service_container')->deleteAll();
@@ -4759,9 +4759,9 @@ function drupal_flush_all_caches() {
       $files[$module] = $data->uri;
     }
   }
-  Drupal::service('kernel')->updateModules($module_handler->getModuleList(), $files);
+  \Drupal::service('kernel')->updateModules($module_handler->getModuleList(), $files);
   // New container, new module handler.
-  $module_handler = Drupal::moduleHandler();
+  $module_handler = \Drupal::moduleHandler();
 
   // Ensure that all modules that are currently supposed to be enabled are
   // actually loaded.
@@ -4781,7 +4781,7 @@ function drupal_flush_all_caches() {
   // Rebuild the menu router based on all rebuilt data.
   // Important: This rebuild must happen last, so the menu router is guaranteed
   // to be based on up to date information.
-  Drupal::service('router.builder')->rebuild();
+  \Drupal::service('router.builder')->rebuild();
   menu_router_rebuild();
 
   // Re-initialize the maintenance theme, if the current request attempted to
@@ -4862,7 +4862,7 @@ function drupal_check_incompatibility($v, $current_version) {
  */
 function archiver_get_extensions() {
   $valid_extensions = array();
-  foreach (Drupal::service('plugin.manager.archiver')->getDefinitions() as $archive) {
+  foreach (\Drupal::service('plugin.manager.archiver')->getDefinitions() as $archive) {
     foreach ($archive['extensions'] as $extension) {
       foreach (explode('.', $extension) as $part) {
         if (!in_array($part, $valid_extensions)) {
@@ -4892,7 +4892,7 @@ function archiver_get_archiver($file) {
   if (!is_file($filepath)) {
     throw new Exception(t('Archivers can only operate on local files: %file not supported', array('%file' => $file)));
   }
-  return Drupal::service('plugin.manager.archiver')->getInstance(array('filepath' => $filepath));
+  return \Drupal::service('plugin.manager.archiver')->getInstance(array('filepath' => $filepath));
 }
 
 /**
@@ -4912,7 +4912,7 @@ function archiver_get_archiver($file) {
 function drupal_get_updaters() {
   $updaters = &drupal_static(__FUNCTION__);
   if (!isset($updaters)) {
-    $updaters = Drupal::moduleHandler()->invokeAll('updater_info');
+    $updaters = \Drupal::moduleHandler()->invokeAll('updater_info');
     drupal_alter('updater_info', $updaters);
     uasort($updaters, 'drupal_sort_weight');
   }
@@ -4932,7 +4932,7 @@ function drupal_get_updaters() {
 function drupal_get_filetransfer_info() {
   $info = &drupal_static(__FUNCTION__);
   if (!isset($info)) {
-    $info = Drupal::moduleHandler()->invokeAll('filetransfer_info');
+    $info = \Drupal::moduleHandler()->invokeAll('filetransfer_info');
     drupal_alter('filetransfer_info', $info);
     uasort($info, 'drupal_sort_weight');
   }
diff --git a/core/includes/config.inc b/core/includes/config.inc
index a3f4a6829e1eebfc4250c363bdbf23dbc325b5e8..56364a80aec090f3f874739d63dc2285ed39d733 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -66,17 +66,17 @@ function ($value) use ($name) {
     $config_to_install = array_merge($config_to_install, $other_module_config);
   }
   if (!empty($config_to_install)) {
-    $storage_comparer = new ExtensionInstallStorageComparer($source_storage, Drupal::service('config.storage'));
+    $storage_comparer = new ExtensionInstallStorageComparer($source_storage, \Drupal::service('config.storage'));
     $storage_comparer->setSourceNames($config_to_install);
     // Only import new config. Changed config is from previous enables and
     // should not be overwritten.
     $storage_comparer->addChangelistCreate();
     $installer = new ConfigInstaller(
       $storage_comparer,
-      Drupal::service('event_dispatcher'),
-      Drupal::service('config.factory'),
-      Drupal::entityManager(),
-      Drupal::lock()
+      \Drupal::service('event_dispatcher'),
+      \Drupal::service('config.factory'),
+      \Drupal::entityManager(),
+      \Drupal::lock()
     );
     $installer->import();
   }
@@ -94,7 +94,7 @@ function config_uninstall_default_config($type, $name) {
   $storage = drupal_container()->get('config.storage');
   $config_names = $storage->listAll($name . '.');
   foreach ($config_names as $config_name) {
-    Drupal::config($config_name)->delete();
+    \Drupal::config($config_name)->delete();
   }
 }
 
@@ -126,7 +126,7 @@ function config_get_storage_names_with_prefix($prefix = '') {
  *   A configuration object.
  */
 function config($name) {
-  return Drupal::config($name);
+  return \Drupal::config($name);
 }
 
 /**
@@ -134,7 +134,7 @@ function config($name) {
  *
  * This allows configuration objects to be created using special configuration
  * contexts eg. global override free or locale using a user preferred language.
- * Calling this function affects all subsequent calls to Drupal::config() until
+ * Calling this function affects all subsequent calls to \Drupal::config() until
  * config_context_leave() is called.
  *
  * @see config_context_leave()
diff --git a/core/includes/entity.api.php b/core/includes/entity.api.php
index 8e60f00c3bef99b3c5c42002bd4d9b25dbf82634..e6e1f7cde65481d760a924e415cc5bc7f6aa8f81 100644
--- a/core/includes/entity.api.php
+++ b/core/includes/entity.api.php
@@ -91,7 +91,7 @@ function hook_entity_bundle_info_alter(&$bundles) {
 function hook_entity_bundle_create($entity_type, $bundle) {
   // When a new bundle is created, the menu needs to be rebuilt to add the
   // Field UI menu item tabs.
-  Drupal::state()->set('menu_rebuild_needed', TRUE);
+  \Drupal::state()->set('menu_rebuild_needed', TRUE);
 }
 
 /**
@@ -108,7 +108,7 @@ function hook_entity_bundle_create($entity_type, $bundle) {
  */
 function hook_entity_bundle_rename($entity_type, $bundle_old, $bundle_new) {
   // Update the settings associated with the bundle in my_module.settings.
-  $config = Drupal::config('my_module.settings');
+  $config = \Drupal::config('my_module.settings');
   $bundle_settings = $config->get('bundle_settings');
   if (isset($bundle_settings[$entity_type][$bundle_old])) {
     $bundle_settings[$entity_type][$bundle_new] = $bundle_settings[$entity_type][$bundle_old];
@@ -129,7 +129,7 @@ function hook_entity_bundle_rename($entity_type, $bundle_old, $bundle_new) {
  */
 function hook_entity_bundle_delete($entity_type, $bundle) {
   // Remove the settings associated with the bundle in my_module.settings.
-  $config = Drupal::config('my_module.settings');
+  $config = \Drupal::config('my_module.settings');
   $bundle_settings = $config->get('bundle_settings');
   if (isset($bundle_settings[$entity_type][$bundle])) {
     unset($bundle_settings[$entity_type][$bundle]);
diff --git a/core/includes/entity.inc b/core/includes/entity.inc
index c5b64d537ed0b6861637f9933a059a24096c93d5..b6b92b02ee1b94ce771de46f559faa6bc89b4e1d 100644
--- a/core/includes/entity.inc
+++ b/core/includes/entity.inc
@@ -29,10 +29,10 @@
  */
 function entity_get_info($entity_type = NULL) {
   if (empty($entity_type)) {
-    return Drupal::entityManager()->getDefinitions();
+    return \Drupal::entityManager()->getDefinitions();
   }
   else {
-    return Drupal::entityManager()->getDefinition($entity_type);
+    return \Drupal::entityManager()->getDefinition($entity_type);
   }
 }
 
@@ -42,8 +42,8 @@ function entity_get_info($entity_type = NULL) {
 function entity_info_cache_clear() {
   drupal_static_reset('entity_get_view_modes');
   // Clear all languages.
-  Drupal::entityManager()->clearCachedDefinitions();
-  Drupal::entityManager()->clearCachedFieldDefinitions();
+  \Drupal::entityManager()->clearCachedDefinitions();
+  \Drupal::entityManager()->clearCachedFieldDefinitions();
 }
 
 /**
@@ -61,10 +61,10 @@ function entity_info_cache_clear() {
  */
 function entity_get_bundles($entity_type = NULL) {
   if (isset($entity_type)) {
-    return Drupal::entityManager()->getBundleInfo($entity_type);
+    return \Drupal::entityManager()->getBundleInfo($entity_type);
   }
   else {
-    return Drupal::entityManager()->getAllBundleInfo();
+    return \Drupal::entityManager()->getAllBundleInfo();
   }
 }
 
@@ -86,10 +86,10 @@ function entity_invoke_bundle_hook($hook, $entity_type, $bundle, $bundle_new = N
 
   // Notify the entity storage controller.
   $method = 'onBundle' . ucfirst($hook);
-  Drupal::entityManager()->getStorageController($entity_type)->$method($bundle, $bundle_new);
+  \Drupal::entityManager()->getStorageController($entity_type)->$method($bundle, $bundle_new);
 
   // Invoke hook_entity_bundle_*() hooks.
-  Drupal::moduleHandler()->invokeAll('entity_bundle_' . $hook, array($entity_type, $bundle, $bundle_new));
+  \Drupal::moduleHandler()->invokeAll('entity_bundle_' . $hook, array($entity_type, $bundle, $bundle_new));
 }
 
 /**
@@ -187,7 +187,7 @@ function entity_get_view_modes($entity_type = NULL) {
  * @see \Drupal\Core\Entity\Query\QueryInterface
  */
 function entity_load($entity_type, $id, $reset = FALSE) {
-  $controller = Drupal::entityManager()->getStorageController($entity_type);
+  $controller = \Drupal::entityManager()->getStorageController($entity_type);
   if ($reset) {
     $controller->resetCache(array($id));
   }
@@ -211,7 +211,7 @@ function entity_load($entity_type, $id, $reset = FALSE) {
  * @see \Drupal\Core\Entity\DatabaseStorageController
  */
 function entity_revision_load($entity_type, $revision_id) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getStorageController($entity_type)
     ->loadRevision($revision_id);
 }
@@ -225,7 +225,7 @@ function entity_revision_load($entity_type, $revision_id) {
  *   The revision ID to delete.
  */
 function entity_revision_delete($entity_type, $revision_id) {
-  Drupal::entityManager()
+  \Drupal::entityManager()
     ->getStorageController($entity_type)
     ->deleteRevision($revision_id);
 }
@@ -257,7 +257,7 @@ function entity_load_by_uuid($entity_type, $uuid, $reset = FALSE) {
   }
   $uuid_key = $entity_info['entity_keys']['uuid'];
 
-  $controller = Drupal::entityManager()->getStorageController($entity_type);
+  $controller = \Drupal::entityManager()->getStorageController($entity_type);
   if ($reset) {
     $controller->resetCache();
   }
@@ -299,7 +299,7 @@ function entity_load_by_uuid($entity_type, $uuid, $reset = FALSE) {
  * @see \Drupal\Core\Entity\Query\QueryInterface
  */
 function entity_load_multiple($entity_type, array $ids = NULL, $reset = FALSE) {
-  $controller = Drupal::entityManager()->getStorageController($entity_type);
+  $controller = \Drupal::entityManager()->getStorageController($entity_type);
   if ($reset) {
     $controller->resetCache($ids);
   }
@@ -319,7 +319,7 @@ function entity_load_multiple($entity_type, array $ids = NULL, $reset = FALSE) {
  *   An array of entity objects indexed by their ids.
  */
 function entity_load_multiple_by_properties($entity_type, array $values) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getStorageController($entity_type)
     ->loadByProperties($values);
 }
@@ -341,7 +341,7 @@ function entity_load_multiple_by_properties($entity_type, array $values) {
  *   The unchanged entity, or FALSE if the entity cannot be loaded.
  */
 function entity_load_unchanged($entity_type, $id) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getStorageController($entity_type)
     ->loadUnchanged($id);
 }
@@ -355,7 +355,7 @@ function entity_load_unchanged($entity_type, $id) {
  *   An array of entity IDs of the entities to delete.
  */
 function entity_delete_multiple($entity_type, array $ids) {
-  $controller = Drupal::entityManager()->getStorageController($entity_type);
+  $controller = \Drupal::entityManager()->getStorageController($entity_type);
   $entities = $controller->loadMultiple($ids);
   $controller->delete($entities);
 }
@@ -373,7 +373,7 @@ function entity_delete_multiple($entity_type, array $ids) {
  *   A new entity object.
  */
 function entity_create($entity_type, array $values) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getStorageController($entity_type)
     ->create($values);
 }
@@ -386,7 +386,7 @@ function entity_create($entity_type, array $values) {
  * @deprecated Use \Drupal\Core\Entity\EntityManager::getStorageController().
  */
 function entity_get_controller($entity_type) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getStorageController($entity_type);
 }
 
@@ -424,7 +424,7 @@ function entity_page_label(EntityInterface $entity, $langcode = NULL) {
  * @deprecated Use \Drupal\Core\Entity\EntityManager::getRenderController().
  */
 function entity_access_controller($entity_type) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getAccessController($entity_type);
 }
 
@@ -452,7 +452,7 @@ function entity_access_controller($entity_type) {
  * @deprecated Use \Drupal\Core\Entity\EntityManager::getFormController().
  */
 function entity_form_controller($entity_type, $operation = 'default') {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getFormController($entity_type, $operation);
 }
 
@@ -469,7 +469,7 @@ function entity_form_controller($entity_type, $operation = 'default') {
  */
 function entity_form_state_defaults(EntityInterface $entity, $operation = 'default') {
   $form_state = array();
-  $controller = Drupal::entityManager()->getFormController($entity->entityType(), $operation);
+  $controller = \Drupal::entityManager()->getFormController($entity->entityType(), $operation);
   $controller->setEntity($entity);
   $form_state['build_info']['callback_object'] = $controller;
   $form_state['build_info']['base_form_id'] = $controller->getBaseFormID();
@@ -514,11 +514,11 @@ function entity_form_submit(EntityInterface $entity, $operation = 'default', &$f
  * @return
  *   The processed form for the given entity and operation.
  *
- * @deprecated Use Drupal::entityManager()->getForm() or _entity_form from a
+ * @deprecated Use \Drupal::entityManager()->getForm() or _entity_form from a
  *   routing.yml file instead of a page callback.
  */
 function entity_get_form(EntityInterface $entity, $operation = 'default', array $form_state = array()) {
-  return Drupal::entityManager()->getForm($entity, $operation, $form_state);
+  return \Drupal::entityManager()->getForm($entity, $operation, $form_state);
 }
 
 /**
@@ -579,7 +579,7 @@ function entity_form_submit_build_entity($entity_type, $entity, $form, &$form_st
  * @deprecated Use \Drupal\Core\Entity\EntityManager::getFormController().
  */
 function entity_list_controller($entity_type) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getListController($entity_type);
 }
 
@@ -595,7 +595,7 @@ function entity_list_controller($entity_type) {
  * @deprecated Use \Drupal\Core\Entity\EntityManager::getFormController().
  */
 function entity_render_controller($entity_type) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getRenderController($entity_type);
 }
 
@@ -614,7 +614,7 @@ function entity_render_controller($entity_type) {
  *   A render array for the entity.
  */
 function entity_view(EntityInterface $entity, $view_mode, $langcode = NULL) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getRenderController($entity->entityType())
     ->view($entity, $view_mode, $langcode);
 }
@@ -635,7 +635,7 @@ function entity_view(EntityInterface $entity, $view_mode, $langcode = NULL) {
  *   entities array passed in $entities.
  */
 function entity_view_multiple(array $entities, $view_mode, $langcode = NULL) {
-  return Drupal::entityManager()
+  return \Drupal::entityManager()
     ->getRenderController(reset($entities)->entityType())
     ->viewMultiple($entities, $view_mode, $langcode);
 }
@@ -858,5 +858,5 @@ function entity_page_access(EntityInterface $entity, $operation = 'view') {
  *   TRUE if the access is granted. FALSE if access is denied.
  */
 function entity_page_create_access($entity_type, $bundle = NULL) {
-  return Drupal::entityManager()->getAccessController($entity_type)->createAccess($bundle);
+  return \Drupal::entityManager()->getAccessController($entity_type)->createAccess($bundle);
 }
diff --git a/core/includes/errors.inc b/core/includes/errors.inc
index 86ef93f2934252eb92abcc059a305cd6f0e59500..1639ba58967f1a587e52ea57924cb47a786b8976 100644
--- a/core/includes/errors.inc
+++ b/core/includes/errors.inc
@@ -222,7 +222,7 @@ function _drupal_log_error($error, $fatal = FALSE) {
     }
   }
 
-  if (Drupal::request()->isXmlHttpRequest()) {
+  if (\Drupal::request()->isXmlHttpRequest()) {
     if ($fatal) {
       if (error_displayable($error)) {
         // When called from JavaScript, simply output the error message.
@@ -295,7 +295,7 @@ function _drupal_log_error($error, $fatal = FALSE) {
  * DRUPAL_BOOTSTRAP_KERNEL or before Drupal is installed. In all other
  * situations the following code is preferred:
  * @code
- * Drupal::config('system.logging')->get('error_level');
+ * \Drupal::config('system.logging')->get('error_level');
  * @endcode
  *
  * @return string
@@ -303,7 +303,7 @@ function _drupal_log_error($error, $fatal = FALSE) {
  */
 function _drupal_get_error_level() {
   try {
-    return Drupal::config('system.logging')->get('error_level');
+    return \Drupal::config('system.logging')->get('error_level');
   }
   catch (Exception $e) {
     // During very early install the cache_config table does not exist.
diff --git a/core/includes/file.inc b/core/includes/file.inc
index f713d1f90f019583c9c0cad2c74f6ab79c57b55e..bb537fb19d02bd91f0d0ec7a2f8cb74d063deb59 100644
--- a/core/includes/file.inc
+++ b/core/includes/file.inc
@@ -190,7 +190,7 @@ function file_get_stream_wrappers($filter = STREAM_WRAPPERS_ALL) {
   $wrappers_storage = &drupal_static(__FUNCTION__);
 
   if (!isset($wrappers_storage)) {
-    $wrappers = Drupal::moduleHandler()->invokeAll('stream_wrappers');
+    $wrappers = \Drupal::moduleHandler()->invokeAll('stream_wrappers');
     foreach ($wrappers as $scheme => $info) {
       // Add defaults.
       $wrappers[$scheme] += array('type' => STREAM_WRAPPERS_NORMAL);
@@ -313,7 +313,7 @@ function file_uri_target($uri) {
  *   'public', 'private' or any other file scheme defined as the default.
  */
 function file_default_scheme() {
-  return Drupal::config('system.file')->get('default_scheme');
+  return \Drupal::config('system.file')->get('default_scheme');
 }
 
 /**
@@ -515,7 +515,7 @@ function file_prepare_directory(&$directory, $options = FILE_MODIFY_PERMISSIONS)
  */
 function file_ensure_htaccess() {
   file_save_htaccess('public://', FALSE);
-  $private_path = Drupal::config('system.file')->get('path.private');
+  $private_path = \Drupal::config('system.file')->get('path.private');
   if (!empty($private_path)) {
     file_save_htaccess('private://', TRUE);
   }
@@ -802,7 +802,7 @@ function file_munge_filename($filename, $extensions, $alerts = TRUE) {
   $original = $filename;
 
   // Allow potentially insecure uploads for very savvy users and admin
-  if (!Drupal::config('system.file')->get('allow_insecure_uploads')) {
+  if (!\Drupal::config('system.file')->get('allow_insecure_uploads')) {
     // Remove any null bytes. See http://php.net/manual/en/security.filesystem.nullbytes.php
     $filename = str_replace(chr(0), '', $filename);
 
@@ -1272,13 +1272,13 @@ function drupal_chmod($uri, $mode = NULL) {
     // that the octal permission numbers can be expressed as integers or strings
     // and will be converted correctly in both cases.
     if (is_dir($uri)) {
-      $mode = octdec(Drupal::config('system.file')->get('chmod.directory'));
+      $mode = octdec(\Drupal::config('system.file')->get('chmod.directory'));
       if (!$mode) {
         $mode = 0775;
       }
     }
     else {
-      $mode = octdec(Drupal::config('system.file')->get('chmod.file'));
+      $mode = octdec(\Drupal::config('system.file')->get('chmod.file'));
       if (!$mode) {
         $mode = 0664;
       }
@@ -1455,8 +1455,8 @@ function drupal_mkdir($uri, $mode = NULL, $recursive = FALSE, $context = NULL) {
     // Configuration system stores default mode as strings.
     $mode = FALSE;
     // During early update there's no container.
-    if (is_object(Drupal::getContainer())) {
-      $mode = octdec(Drupal::config('system.file')->get('chmod.directory'));
+    if (is_object(\Drupal::getContainer())) {
+      $mode = octdec(\Drupal::config('system.file')->get('chmod.directory'));
     }
     if (!$mode) {
       $mode = 0775;
@@ -1608,7 +1608,7 @@ function drupal_tempnam($directory, $prefix) {
  *   A string containing the path to the temporary directory.
  */
 function file_directory_temp() {
-  $config = Drupal::config('system.file');
+  $config = \Drupal::config('system.file');
   $temporary_directory = $config->get('path.temporary');
   if (empty($temporary_directory)) {
     $temporary_directory = file_directory_os_temp();
diff --git a/core/includes/form.inc b/core/includes/form.inc
index 8aee8f02e51a6afcd9f5044e9ed9c9cf775f86f2..76106ee14384aa38e81e3e6a99a8c7c81ce3c7cd 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -545,10 +545,10 @@ function drupal_rebuild_form($form_id, &$form_state, $old_form = NULL) {
  * Fetches a form from the cache.
  */
 function form_get_cache($form_build_id, &$form_state) {
-  if ($form = Drupal::keyValueExpirable('form')->get($form_build_id)) {
+  if ($form = \Drupal::keyValueExpirable('form')->get($form_build_id)) {
     global $user;
     if ((isset($form['#cache_token']) && drupal_valid_token($form['#cache_token'])) || (!isset($form['#cache_token']) && $user->isAnonymous())) {
-      if ($stored_form_state = Drupal::keyValueExpirable('form_state')->get($form_build_id)) {
+      if ($stored_form_state = \Drupal::keyValueExpirable('form_state')->get($form_build_id)) {
         // Re-populate $form_state for subsequent rebuilds.
         $form_state = $stored_form_state + $form_state;
 
@@ -582,12 +582,12 @@ function form_set_cache($form_build_id, $form, $form_state) {
     if ($GLOBALS['user']->isAuthenticated()) {
       $form['#cache_token'] = drupal_get_token();
     }
-    Drupal::keyValueExpirable('form')->setWithExpire($form_build_id, $form, $expire);
+    \Drupal::keyValueExpirable('form')->setWithExpire($form_build_id, $form, $expire);
   }
 
   // Cache form state.
   if ($data = array_diff_key($form_state, array_flip(form_state_keys_no_cache()))) {
-    Drupal::keyValueExpirable('form_state')->setWithExpire($form_build_id, $data, $expire);
+    \Drupal::keyValueExpirable('form_state')->setWithExpire($form_build_id, $data, $expire);
   }
 }
 
@@ -820,7 +820,7 @@ function drupal_retrieve_form($form_id, &$form_state) {
     // So, we call the hook if $forms isn't yet populated, OR if it doesn't
     // yet have an entry for the requested form_id.
     if (!isset($forms) || !isset($forms[$form_id])) {
-      $forms = Drupal::moduleHandler()->invokeAll('forms', array($form_id, $args));
+      $forms = \Drupal::moduleHandler()->invokeAll('forms', array($form_id, $args));
     }
     $form_definition = $forms[$form_id];
     if (isset($form_definition['callback arguments'])) {
@@ -1346,8 +1346,8 @@ function drupal_redirect_form($form_state) {
         }
       }
     }
-    $url = url(Drupal::request()->attributes->get('_system_path'), array(
-      'query' => Drupal::request()->query->all(),
+    $url = url(\Drupal::request()->attributes->get('_system_path'), array(
+      'query' => \Drupal::request()->query->all(),
       'absolute' => TRUE,
     ));
     return new RedirectResponse($url);
@@ -4106,8 +4106,8 @@ function form_process_autocomplete($element, &$form_state) {
   if (!empty($element['#autocomplete_route_name'])) {
     $parameters = isset($element['#autocomplete_route_parameters']) ? $element['#autocomplete_route_parameters'] : array();
 
-    $path = Drupal::urlGenerator()->generate($element['#autocomplete_route_name'], $parameters);
-    $access = Drupal::service('access_manager')->checkNamedRoute($element['#autocomplete_route_name'], $parameters);
+    $path = \Drupal::urlGenerator()->generate($element['#autocomplete_route_name'], $parameters);
+    $access = \Drupal::service('access_manager')->checkNamedRoute($element['#autocomplete_route_name'], $parameters);
   }
   elseif (!empty($element['#autocomplete_path'])) {
     $path = url($element['#autocomplete_path'], array('absolute' => TRUE));
@@ -4600,7 +4600,7 @@ function form_process_weight($element) {
   $element['#is_weight'] = TRUE;
 
   // If the number of options is small enough, use a select field.
-  $max_elements = Drupal::config('system.site')->get('weight_select_max');
+  $max_elements = \Drupal::config('system.site')->get('weight_select_max');
   if ($element['#delta'] <= $max_elements) {
     $element['#type'] = 'select';
     for ($n = (-1 * $element['#delta']); $n <= $element['#delta']; $n++) {
@@ -4881,11 +4881,11 @@ function _form_set_attributes(&$element, $class = array()) {
  *   A response object.
  */
 function _drupal_form_send_response(Response $response) {
-  $request = Drupal::request();
-  $kernel = Drupal::service('http_kernel');
+  $request = \Drupal::request();
+  $kernel = \Drupal::service('http_kernel');
   $event = new FilterResponseEvent($kernel, $request, $kernel::MASTER_REQUEST, $response);
 
-  Drupal::service('event_dispatcher')->dispatch(KernelEvents::RESPONSE, $event);
+  \Drupal::service('event_dispatcher')->dispatch(KernelEvents::RESPONSE, $event);
   // Prepare and send the response.
   $event->getResponse()
     ->prepare($request)
@@ -5173,14 +5173,14 @@ function batch_process($redirect = NULL, $url = 'batch', $redirect_callback = NU
 
       // Clear the way for the redirection to the batch processing page, by
       // saving and unsetting the 'destination', if there is any.
-      $request = Drupal::request();
+      $request = \Drupal::request();
       if ($request->query->has('destination')) {
         $batch['destination'] = $request->query->get('destination');
         $request->query->remove('destination');
       }
 
       // Store the batch.
-      Drupal::service('batch.storage')->create($batch);
+      \Drupal::service('batch.storage')->create($batch);
 
       // Set the batch number in the session to guarantee that it will stay alive.
       $_SESSION['batches'][$batch['id']] = TRUE;
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 1aea9284b05d48c35a342281079a3edfe3389ab8..b4613420a4c5873b50f2e96b0f20b8e492da9b93 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -329,7 +329,7 @@ function install_begin_request(&$install_state) {
   $container = new ContainerBuilder();
   // Register the translation services.
   install_register_translation_service($container);
-  Drupal::setContainer($container);
+  \Drupal::setContainer($container);
 
   // Check existing settings.php.
   $install_state['database_verified'] = install_verify_database_settings();
@@ -444,18 +444,18 @@ function install_begin_request(&$install_state) {
   // so it is available to the rest of the installation process.
   $container->set('request', $request);
 
-  Drupal::setContainer($container);
+  \Drupal::setContainer($container);
 
   // Set up $language, so t() caller functions will still work.
   drupal_language_initialize();
   // Add in installation language if present.
   if (isset($install_state['parameters']['langcode'])) {
-    Drupal::translation()->setDefaultLangcode($install_state['parameters']['langcode']);
+    \Drupal::translation()->setDefaultLangcode($install_state['parameters']['langcode']);
   }
 
   require_once __DIR__ . '/ajax.inc';
 
-  $module_handler = Drupal::moduleHandler();
+  $module_handler = \Drupal::moduleHandler();
   if (!$module_handler->moduleExists('system')) {
     // Override the module list with a minimal set of modules.
     $module_handler->setModuleList(array('system' => 'core/modules/system/system.module'));
@@ -652,7 +652,7 @@ function install_run_task($task, &$install_state) {
     // any output from the batch process, until the task is complete.
     elseif ($current_batch == $function) {
       include_once __DIR__ . '/batch.inc';
-      $output = _batch_page(Drupal::request());
+      $output = _batch_page(\Drupal::request());
       // Because Batch API now returns a JSON response for intermediary steps,
       // but the installer doesn't handle Response objects yet, just send the
       // output here and emulate the old model.
@@ -1005,7 +1005,7 @@ function install_base_system(&$install_state) {
   // after all the dependencies have been installed.
   $modules[] = drupal_get_profile();
 
-  Drupal::state()->set('install_profile_modules', array_diff($modules, array('system')));
+  \Drupal::state()->set('install_profile_modules', array_diff($modules, array('system')));
   $install_state['database_tables_exist'] = TRUE;
 }
 
@@ -1421,7 +1421,7 @@ function install_select_profile_form($form, &$form_state, $install_state) {
  */
 function install_find_translations() {
   $translations = array();
-  $files = Drupal::service('string_translator.file_translation')->findTranslationFiles();
+  $files = \Drupal::service('string_translator.file_translation')->findTranslationFiles();
   // English does not need a translation file.
   array_unshift($files, (object) array('name' => 'en'));
   foreach ($files as $uri => $file) {
@@ -1653,7 +1653,7 @@ function install_retrieve_file($uri, $destination) {
   }
 
   try {
-    $request = Drupal::httpClient()->get($uri, array('Accept' => 'text/plain'));
+    $request = \Drupal::httpClient()->get($uri, array('Accept' => 'text/plain'));
     $data = $request->send()->getBody(TRUE);
     if (empty($data)) {
       return FALSE;
@@ -1676,7 +1676,7 @@ function install_retrieve_file($uri, $destination) {
  */
 function install_check_localization_server($uri) {
   try {
-    $request = Drupal::httpClient()->head($uri);
+    $request = \Drupal::httpClient()->head($uri);
     $request->send();
     return TRUE;
   }
@@ -1697,8 +1697,8 @@ function install_check_localization_server($uri) {
  *   Associative array containing 'core' and 'version' of the release.
  */
 function install_get_localization_release() {
-  if (strpos(Drupal::VERSION, 'dev')) {
-    list($version, ) = explode('-', Drupal::VERSION);
+  if (strpos(\Drupal::VERSION, 'dev')) {
+    list($version, ) = explode('-', \Drupal::VERSION);
     list($major, $minor) = explode('.', $version);
 
     // Calculate the major and minor release numbers to fall back to.
@@ -1712,7 +1712,7 @@ function install_get_localization_release() {
     $release = "$major.$minor";
   }
   else {
-    $release = Drupal::VERSION;
+    $release = \Drupal::VERSION;
   }
 
   return array(
@@ -1781,9 +1781,9 @@ function install_bootstrap_full() {
  *   The batch definition.
  */
 function install_profile_modules(&$install_state) {
-  $modules = Drupal::state()->get('install_profile_modules') ?: array();
+  $modules = \Drupal::state()->get('install_profile_modules') ?: array();
   $files = system_rebuild_module_data();
-  Drupal::state()->delete('install_profile_modules');
+  \Drupal::state()->delete('install_profile_modules');
 
   // Always install required modules first. Respect the dependencies between
   // the modules.
@@ -1979,7 +1979,7 @@ function install_import_translations_remaining(&$install_state) {
  * @see install_tasks()
  */
 function install_update_configuration_translations(&$install_state) {
-  Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
+  \Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
   return locale_config_batch_update_components(array(), array($install_state['parameters']['langcode']));
 }
 
@@ -2010,7 +2010,7 @@ function install_finished(&$install_state) {
   // Ensure the URL that is generated for the home page does not have 'install.php'
   // in it.
   $request = Request::createFromGlobals();
-  $generator = Drupal::urlGenerator();
+  $generator = \Drupal::urlGenerator();
   $generator->setBasePath(str_replace('/core', '', $request->getBasePath()) . '/');
   $generator->setScriptPath('');
   $url = $generator->generateFromPath('');
@@ -2443,12 +2443,12 @@ function _install_configure_form($form, &$form_state, &$install_state) {
     '#title' => t('Regional settings'),
   );
 
-  $countries = Drupal::service('country_manager')->getList();
+  $countries = \Drupal::service('country_manager')->getList();
   $form['regional_settings']['site_default_country'] = array(
     '#type' => 'select',
     '#title' => t('Default country'),
     '#empty_value' => '',
-    '#default_value' => Drupal::config('system.date')->get('country.default'),
+    '#default_value' => \Drupal::config('system.date')->get('country.default'),
     '#options' => $countries,
     '#description' => t('Select the default country for the site.'),
     '#weight' => 0,
@@ -2516,13 +2516,13 @@ function install_configure_form_validate($form, &$form_state) {
 function install_configure_form_submit($form, &$form_state) {
   global $user;
 
-  Drupal::config('system.site')
+  \Drupal::config('system.site')
     ->set('name', $form_state['values']['site_name'])
     ->set('mail', $form_state['values']['site_mail'])
     ->set('langcode', language_default()->id)
     ->save();
 
-  Drupal::config('system.date')
+  \Drupal::config('system.date')
     ->set('timezone.default', $form_state['values']['date_default_timezone'])
     ->set('country.default', $form_state['values']['site_default_country'])
     ->save();
@@ -2534,7 +2534,7 @@ function install_configure_form_submit($form, &$form_state) {
     // Add the site maintenance account's email address to the list of
     // addresses to be notified when updates are available, if selected.
     if ($form_state['values']['update_status_module'][2]) {
-      Drupal::config('update.settings')->set('notification.emails', array($form_state['values']['account']['mail']))->save();
+      \Drupal::config('update.settings')->set('notification.emails', array($form_state['values']['account']['mail']))->save();
     }
   }
 
diff --git a/core/includes/install.inc b/core/includes/install.inc
index c308a2da2673021517c046e83784cadceec458a1..fdf8e84bcf0f665acbcfd138e7f4a97263adb686 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -627,18 +627,18 @@ function drupal_install_system() {
   require_once DRUPAL_ROOT . '/' . $system_path . '/system.install';
   $system_versions = drupal_get_schema_versions('system');
   $system_version = $system_versions ? max($system_versions) : SCHEMA_INSTALLED;
-  Drupal::keyValue('system.schema')->set('system', $system_version);
+  \Drupal::keyValue('system.schema')->set('system', $system_version);
 
   // System module needs to be enabled and the system/module lists need to be
   // reset first in order to allow config_install_default_config() to invoke
   // config import callbacks.
   // @todo Installation profiles may override the system.module config object.
-  Drupal::config('system.module')
+  \Drupal::config('system.module')
     ->set('enabled.system', 0)
     ->save();
 
   // Update the module list to include it.
-  Drupal::moduleHandler()->setModuleList(array('system' => $system_path . '/system.module'));
+  \Drupal::moduleHandler()->setModuleList(array('system' => $system_path . '/system.module'));
 
   config_install_default_config('module', 'system');
 
diff --git a/core/includes/language.inc b/core/includes/language.inc
index 44e91c1b2aec3be19d5ffd092da25ee553a5e414..6b5a757454a8092462bf0e2f71b9bb1ba2484820 100644
--- a/core/includes/language.inc
+++ b/core/includes/language.inc
@@ -161,7 +161,7 @@ function language_types_info() {
   $language_types = &drupal_static(__FUNCTION__);
 
   if (!isset($language_types)) {
-    $language_types = Drupal::moduleHandler()->invokeAll('language_types_info');
+    $language_types = \Drupal::moduleHandler()->invokeAll('language_types_info');
     // Let other modules alter the list of language types.
     drupal_alter('language_types_info', $language_types);
   }
@@ -180,7 +180,7 @@ function language_types_info() {
  *   An array of language type names.
  */
 function language_types_get_configurable() {
-  $configurable = Drupal::config('system.language.types')->get('configurable');
+  $configurable = \Drupal::config('system.language.types')->get('configurable');
   return $configurable ? $configurable : array();
 }
 
@@ -192,7 +192,7 @@ function language_types_get_configurable() {
  */
 function language_types_disable($types) {
   $configurable = language_types_get_configurable();
-  Drupal::config('system.language.types')->set('configurable', array_diff($configurable, $types))->save();
+  \Drupal::config('system.language.types')->set('configurable', array_diff($configurable, $types))->save();
 }
 
 /**
@@ -252,7 +252,7 @@ function language_types_set(array $configurable_language_types) {
   }
 
   // Store the language type configuration.
-  $config = Drupal::config('system.language.types');
+  $config = \Drupal::config('system.language.types');
   $config->set('configurable', array_keys(array_filter($language_types)))->save();
   $config->set('all', array_keys($language_types))->save();
 
@@ -413,7 +413,7 @@ function language_negotiation_info() {
 
   if (!isset($negotiation_info)) {
     // Collect all the module-defined language negotiation methods.
-    $negotiation_info = Drupal::moduleHandler()->invokeAll('language_negotiation_info');
+    $negotiation_info = \Drupal::moduleHandler()->invokeAll('language_negotiation_info');
     $languages = language_list();
     $selected_language = $languages[language_from_selected($languages)];
     $description = 'Language based on a selected language. ';
@@ -493,7 +493,7 @@ function language_negotiation_method_invoke($method_id, $method = NULL, $request
   *   A valid language code on success, FALSE otherwise.
   */
 function language_from_selected($languages) {
-  $langcode = (string) Drupal::config('language.negotiation')->get('selected_langcode');
+  $langcode = (string) \Drupal::config('language.negotiation')->get('selected_langcode');
   // Replace the site's default langcode by its real value.
   if ($langcode == 'site_default') {
     $langcode = language_default()->id;
diff --git a/core/includes/mail.inc b/core/includes/mail.inc
index 5c8117d9b6f9377381f88805a4ebac2b01a2e8d2..20f01da05142f8c5649ef1b6c0984316db053c9f 100644
--- a/core/includes/mail.inc
+++ b/core/includes/mail.inc
@@ -119,7 +119,7 @@
  *   accepted at php-level, which still doesn't guarantee it to be delivered.)
  */
 function drupal_mail($module, $key, $to, $langcode, $params = array(), $from = NULL, $send = TRUE) {
-  $site_config = Drupal::config('system.site');
+  $site_config = \Drupal::config('system.site');
   $site_mail = $site_config->get('mail');
   if (empty($site_mail)) {
     $site_mail = ini_get('sendmail_from');
@@ -214,7 +214,7 @@ function drupal_mail($module, $key, $to, $langcode, $params = array(), $from = N
  * @see \Drupal\Core\Mail\MailFactory::get()
  */
 function drupal_mail_system($module, $key) {
-  return Drupal::service('mail.factory')->get($module, $key);
+  return \Drupal::service('mail.factory')->get($module, $key);
 }
 
 /**
diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index 227dd3eb6df4dc7d28b59533c5acbfc34d67f118..f289cbbe1bd9439a78fd2d40bd0f6b99dd8cf854 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -339,7 +339,7 @@ function menu_get_ancestors($parts) {
   $ancestors = array();
   $length =  $number_parts - 1;
   $end = (1 << $number_parts) - 1;
-  $masks = Drupal::state()->get('menu.masks');
+  $masks = \Drupal::state()->get('menu.masks');
   // If the optimized menu.masks array is not available use brute force to get
   // the correct $ancestors and $placeholders returned. Do not use this as the
   // default value of the menu.masks variable to avoid building such a big
@@ -473,7 +473,7 @@ function menu_get_item($path = NULL, $router_item = NULL) {
   if (!isset($router_items[$path])) {
     // Rebuild if we know it's needed, or if the menu masks are missing which
     // occurs rarely, likely due to a race condition of multiple rebuilds.
-    if (Drupal::state()->get('menu_rebuild_needed') || !Drupal::state()->get('menu.masks')) {
+    if (\Drupal::state()->get('menu_rebuild_needed') || !\Drupal::state()->get('menu.masks')) {
       menu_router_rebuild();
     }
     $original_map = arg(NULL, $path);
@@ -783,7 +783,7 @@ function _menu_translate(&$router_item, $map, $to_arg = FALSE) {
     // with the link map.
     $map = $link_map;
 
-    $route_provider = Drupal::getContainer()->get('router.route_provider');
+    $route_provider = \Drupal::getContainer()->get('router.route_provider');
     $route = $route_provider->getRouteByName($router_item['route_name']);
     $router_item['access'] = menu_item_route_access($route, $router_item['href'], $map);
   }
@@ -975,7 +975,7 @@ function menu_item_route_access(Route $route, $href, &$map) {
   // Attempt to match this path to provide a fully built request to the
   // access checker.
   try {
-    $request->attributes->add(Drupal::service('router.dynamic')->matchRequest($request));
+    $request->attributes->add(\Drupal::service('router.dynamic')->matchRequest($request));
   }
   catch (NotFoundHttpException $e) {
     return FALSE;
@@ -996,7 +996,7 @@ function menu_item_route_access(Route $route, $href, &$map) {
     }
   }
 
-  return Drupal::service('access_manager')->check($route, $request);
+  return \Drupal::service('access_manager')->check($route, $request);
 }
 
 /**
@@ -1358,13 +1358,13 @@ function menu_tree_page_data($menu_name, $max_depth = NULL, $only_active_trail =
           }
           $parents = $active_trail;
 
-          $expanded = Drupal::state()->get('menu_expanded');
+          $expanded = \Drupal::state()->get('menu_expanded');
           // Check whether the current menu has any links set to be expanded.
           if (!$only_active_trail && $expanded && in_array($menu_name, $expanded)) {
             // Collect all the links set to be expanded, and then add all of
             // their children to the list as well.
             do {
-              $query = Drupal::entityQuery('menu_link')
+              $query = \Drupal::entityQuery('menu_link')
                 ->condition('menu_name', $menu_name)
                 ->condition('expanded', 1)
                 ->condition('has_children', 1)
@@ -1459,7 +1459,7 @@ function _menu_build_tree($menu_name, array $parameters = array()) {
   }
 
   if (!isset($trees[$tree_cid])) {
-    $query = Drupal::entityQuery('menu_link');
+    $query = \Drupal::entityQuery('menu_link');
     for ($i = 1; $i <= MENU_MAX_DEPTH; $i++) {
       $query->sort('p' . $i, 'ASC');
     }
@@ -1769,7 +1769,7 @@ function menu_get_active_help() {
 
   $arg = drupal_help_arg(arg(NULL));
 
-  foreach (Drupal::moduleHandler()->getImplementations('help') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('help') as $module) {
     $function = $module . '_help';
     // Lookup help for this path.
     if ($help = $function($router_path, $arg)) {
@@ -1799,7 +1799,7 @@ function menu_get_custom_theme($initialize = FALSE) {
     // First allow modules to dynamically set a custom theme for the current
     // page. Since we can only have one, the last module to return a valid
     // theme takes precedence.
-    $custom_themes = array_filter(Drupal::moduleHandler()->invokeAll('custom_theme'), 'drupal_theme_access');
+    $custom_themes = array_filter(\Drupal::moduleHandler()->invokeAll('custom_theme'), 'drupal_theme_access');
     if (!empty($custom_themes)) {
       $custom_theme = array_pop($custom_themes);
     }
@@ -1841,7 +1841,7 @@ function menu_list_system_menus() {
  * Returns an array of links to be rendered as the Main menu.
  */
 function menu_main_menu() {
-  $config = Drupal::config('menu.settings');
+  $config = \Drupal::config('menu.settings');
   $menu_enabled = module_exists('menu');
   // When menu module is not enabled, we need a hardcoded default value.
   $main_links_source = $menu_enabled ? $config->get('main_links') : 'main';
@@ -1852,7 +1852,7 @@ function menu_main_menu() {
  * Returns an array of links to be rendered as the Secondary links.
  */
 function menu_secondary_menu() {
-  $config = Drupal::config('menu.settings');
+  $config = \Drupal::config('menu.settings');
   $menu_enabled = module_exists('menu');
   // When menu module is not enabled, we need a hardcoded default value.
   $main_links_source = $menu_enabled ? $config->get('main_links') : 'main';
@@ -2145,9 +2145,9 @@ function menu_local_tasks($level = 0) {
     $tabs = array_values($tabs);
     $data['tabs'] = $tabs;
     // Look for route-based tabs.
-    $route_name = Drupal::request()->attributes->get('_route');
+    $route_name = \Drupal::request()->attributes->get('_route');
     if (!empty($route_name)) {
-      $manager = Drupal::service('plugin.manager.menu.local_task');
+      $manager = \Drupal::service('plugin.manager.menu.local_task');
       $local_tasks = $manager->getTasksBuild($route_name);
       foreach ($local_tasks as $level => $items) {
         $data['tabs'][$level] = empty($data['tabs'][$level]) ? $items : array_merge($data['tabs'][$level], $items);
@@ -2155,7 +2155,7 @@ function menu_local_tasks($level = 0) {
     }
 
     // Allow modules to dynamically add further tasks.
-    $module_handler = Drupal::moduleHandler();
+    $module_handler = \Drupal::moduleHandler();
     foreach ($module_handler->getImplementations('menu_local_tasks') as $module) {
       $function = $module . '_menu_local_tasks';
       $function($data, $router_item, $root_path);
@@ -2309,7 +2309,7 @@ function menu_secondary_local_tasks() {
 function menu_get_local_actions() {
   $links = menu_local_tasks();
   $router_item = menu_get_item();
-  $manager = Drupal::service('plugin.manager.menu.local_action');
+  $manager = \Drupal::service('plugin.manager.menu.local_action');
   $local_actions = $manager->getActionsForRoute($router_item['route_name']);
   foreach ($local_actions as $plugin) {
     $route_path = $manager->getPath($plugin);
@@ -2396,7 +2396,7 @@ function menu_set_active_menu_names($menu_names = NULL) {
     $active = $menu_names;
   }
   elseif (!isset($active)) {
-    $config = Drupal::config('system.menu');
+    $config = \Drupal::config('system.menu');
     $active = $config->get('active_menus_default') ?: array_keys(menu_list_system_menus());
   }
   return $active;
@@ -2652,7 +2652,7 @@ function menu_get_active_breadcrumb() {
 
     // Don't show a link to the current page in the breadcrumb trail.
     $end = end($active_trail);
-    if (Drupal::request()->attributes->get('_system_path') == $end['href']) {
+    if (\Drupal::request()->attributes->get('_system_path') == $end['href']) {
       array_pop($active_trail);
     }
 
@@ -2717,7 +2717,7 @@ function menu_cache_clear_all() {
  * Resets the menu system static cache.
  */
 function menu_reset_static_cache() {
-  Drupal::entityManager()
+  \Drupal::entityManager()
     ->getStorageController('menu_link')->resetCache();
   drupal_static_reset('_menu_build_tree');
   drupal_static_reset('menu_tree');
@@ -2755,7 +2755,7 @@ function menu_router_rebuild() {
     menu_cache_clear_all();
     _menu_clear_page_cache();
     // Indicate that the menu has been successfully rebuilt.
-    Drupal::state()->delete('menu_rebuild_needed');
+    \Drupal::state()->delete('menu_rebuild_needed');
   }
   catch (Exception $e) {
     $transaction->rollback();
@@ -2776,7 +2776,7 @@ function menu_router_build($save = FALSE) {
   // We need to manually call each module so that we can know which module
   // a given item came from.
   $callbacks = array();
-  foreach (Drupal::moduleHandler()->getImplementations('menu') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('menu') as $module) {
     $router_items = call_user_func($module . '_menu');
     if (isset($router_items) && is_array($router_items)) {
       foreach (array_keys($router_items) as $path) {
@@ -2823,7 +2823,7 @@ function menu_router_build($save = FALSE) {
  *   The translated path pattern from the route.
  */
 function _menu_router_translate_route($route_name) {
-  $outline = Drupal::service('router.route_provider')
+  $outline = \Drupal::service('router.route_provider')
     ->getRouteByName($route_name)
     ->compile()
     ->getPatternOutline();
@@ -2865,7 +2865,7 @@ function _menu_navigation_links_rebuild($menu) {
     // when possible.
     return;
   }
-  $menu_link_controller = Drupal::entityManager()
+  $menu_link_controller = \Drupal::entityManager()
     ->getStorageController('menu_link');
 
   // Add normal and suggested items as links.
@@ -2951,7 +2951,7 @@ function _menu_navigation_links_rebuild($menu) {
   }
 
   // Find any item whose router path does not exist any more.
-  $query = Drupal::entityQuery('menu_link')
+  $query = \Drupal::entityQuery('menu_link')
     ->condition('router_path', $paths, 'NOT IN')
     ->condition('external', 0)
     ->condition('updated', 0)
@@ -2978,7 +2978,7 @@ function _menu_navigation_links_rebuild($menu) {
 function menu_load_links($menu_name) {
   $links = array();
 
-  $query = Drupal::entityQuery('menu_link')
+  $query = \Drupal::entityQuery('menu_link')
     ->condition('menu_name', $menu_name)
     // Order by weight so as to be helpful for menus that are only one level
     // deep.
@@ -3030,7 +3030,7 @@ function _menu_clear_page_cache() {
  */
 function _menu_set_expanded_menus() {
   $names = db_query("SELECT menu_name FROM {menu_links} WHERE expanded <> 0 GROUP BY menu_name")->fetchCol();
-  Drupal::state()->set('menu_expanded', $names);
+  \Drupal::state()->set('menu_expanded', $names);
 }
 
 /**
@@ -3305,8 +3305,8 @@ function _menu_router_build($callbacks, $save = FALSE) {
     $path_roots = array_values($path_roots);
     // Update the path roots variable and reset the path alias whitelist cache
     // if the list has changed.
-    if ($path_roots != Drupal::state()->get('menu_path_roots')) {
-      Drupal::state()->set('menu_path_roots', array_values($path_roots));
+    if ($path_roots != \Drupal::state()->get('menu_path_roots')) {
+      \Drupal::state()->set('menu_path_roots', array_values($path_roots));
       drupal_container()->get('path.alias_manager')->cacheClear();
     }
     _menu_router_save($menu, $masks);
@@ -3394,7 +3394,7 @@ function _menu_router_save($menu, $masks) {
   // Insert any remaining records.
   $insert->execute();
   // Store the masks.
-  Drupal::state()->set('menu.masks', $masks);
+  \Drupal::state()->set('menu.masks', $masks);
 
   return $menu;
 }
@@ -3418,7 +3418,7 @@ function _menu_router_save($menu, $masks) {
  */
 function _menu_site_is_offline($check_only = FALSE) {
   // Check if site is in maintenance mode.
-  if (Drupal::state()->get('system.maintenance_mode')) {
+  if (\Drupal::state()->get('system.maintenance_mode')) {
     if (user_access('access site in maintenance mode')) {
       // Ensure that the maintenance mode message is displayed only once
       // (allowing for page redirects) and specifically suppress its display on
diff --git a/core/includes/module.inc b/core/includes/module.inc
index 1a32c09ff48c2ae064b44f4414572407ffbd1a6c..daaeb4b6b4c13acdcee3716f1f0fca8801cc285d 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -24,7 +24,7 @@
  * @see list_themes()
  *
  * @todo There are too many layers/levels of caching involved for system_list()
- *   data. Consider to add a Drupal::config($name, $cache = TRUE) argument to allow
+ *   data. Consider to add a \Drupal::config($name, $cache = TRUE) argument to allow
  *   callers like system_list() to force-disable a possible configuration
  *   storage controller cache or some other way to circumvent it/take it over.
  */
@@ -39,12 +39,12 @@ function system_list($type) {
       'filepaths' => array(),
     );
     // Build a list of themes.
-    $enabled_themes = (array) Drupal::config('system.theme')->get('enabled');
+    $enabled_themes = (array) \Drupal::config('system.theme')->get('enabled');
     // @todo Themes include all themes, including disabled/uninstalled. This
     //   system.theme.data state will go away entirely as soon as themes have
     //   a proper installation status.
     // @see http://drupal.org/node/1067408
-    $theme_data = Drupal::state()->get('system.theme.data');
+    $theme_data = \Drupal::state()->get('system.theme.data');
     if (empty($theme_data)) {
       // @todo: system_list() may be called from _drupal_bootstrap_code(), in
       // which case system.module is not loaded yet.
@@ -119,7 +119,7 @@ function system_list_reset() {
   // will cause system_list_reset() to be called, but theme data is not
   // necessarily rebuilt afterwards.
   // @todo Obsolete with proper installation status for themes.
-  Drupal::state()->delete('system.theme.data');
+  \Drupal::state()->delete('system.theme.data');
 }
 
 /**
@@ -206,30 +206,30 @@ function module_load_include($type, $module, $name = NULL) {
  * Enables or installs a given list of modules.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->enable($module_list, $enable_dependencies = TRUE).
+ *   \Drupal::moduleHandler()->enable($module_list, $enable_dependencies = TRUE).
  */
 function module_enable($module_list, $enable_dependencies = TRUE) {
-  return Drupal::moduleHandler()->enable($module_list, $enable_dependencies);
+  return \Drupal::moduleHandler()->enable($module_list, $enable_dependencies);
 }
 
 /**
  * Disables a given set of modules.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->disable($module_list, $disable_dependents = TRUE).
+ *   \Drupal::moduleHandler()->disable($module_list, $disable_dependents = TRUE).
  */
 function module_disable($module_list, $disable_dependents = TRUE) {
-  Drupal::moduleHandler()->disable($module_list, $disable_dependents);
+  \Drupal::moduleHandler()->disable($module_list, $disable_dependents);
 }
 
 /**
  * Uninstalls a given list of disabled modules.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::moduleHandler()->uninstall($module_list, $uninstall_dependents = TRUE).
+ *   \Drupal::moduleHandler()->uninstall($module_list, $uninstall_dependents = TRUE).
  */
 function module_uninstall($module_list = array(), $uninstall_dependents = TRUE) {
-  return Drupal::moduleHandler()->uninstall($module_list, $uninstall_dependents);
+  return \Drupal::moduleHandler()->uninstall($module_list, $uninstall_dependents);
 }
 
 /**
@@ -324,7 +324,7 @@ function drupal_required_modules() {
  */
 function module_set_weight($module, $weight) {
   // Update the module weight in the config file that contains it.
-  $module_config = Drupal::config('system.module');
+  $module_config = \Drupal::config('system.module');
   if ($module_config->get("enabled.$module") !== NULL) {
     $module_config
       ->set("enabled.$module", $weight)
@@ -333,7 +333,7 @@ function module_set_weight($module, $weight) {
 
     // Prepare the new module list, sorted by weight, including filenames.
     // @see module_enable()
-    $module_handler = Drupal::moduleHandler();
+    $module_handler = \Drupal::moduleHandler();
     $current_module_filenames = $module_handler->getModuleList();
     $current_modules = array_fill_keys(array_keys($current_module_filenames), 0);
     $current_modules = module_config_sort(array_merge($current_modules, $module_config->get('enabled')));
@@ -345,7 +345,7 @@ function module_set_weight($module, $weight) {
     $module_handler->setModuleList($module_filenames);
     return;
   }
-  $disabled_config = Drupal::config('system.module.disabled');
+  $disabled_config = \Drupal::config('system.module.disabled');
   if ($disabled_config->get($module) !== NULL) {
     $disabled_config
       ->set($module, $weight)
diff --git a/core/includes/pager.inc b/core/includes/pager.inc
index 4654012147ee94cf47bc1a04bb8dd4e52b2c93a6..67fbf5d2520a894883591da4a53647f218e5cbd8 100644
--- a/core/includes/pager.inc
+++ b/core/includes/pager.inc
@@ -27,7 +27,7 @@
  * @see pager_default_initialize()
  */
 function pager_find_page($element = 0) {
-  $page = Drupal::request()->query->get('page', '');
+  $page = \Drupal::request()->query->get('page', '');
   $page_array = explode(',', $page);
   if (!isset($page_array[$element])) {
     $page_array[$element] = 0;
@@ -137,7 +137,7 @@ function pager_default_initialize($total, $limit, $element = 0) {
 function pager_get_query_parameters() {
   $query = &drupal_static(__FUNCTION__);
   if (!isset($query)) {
-    $query = Url::filterQueryParameters(Drupal::request()->query->all(), array('page'));
+    $query = Url::filterQueryParameters(\Drupal::request()->query->all(), array('page'));
   }
   return $query;
 }
@@ -426,7 +426,7 @@ function pager_query_add_page(array $query, $element, $index) {
   // Determine the first result to display on the linked page.
   $page_new = pager_load_array($index, $element, $pager_page_array);
 
-  $page = Drupal::request()->query->get('page', '');
+  $page = \Drupal::request()->query->get('page', '');
   if ($new_page = implode(',', pager_load_array($page_new[$element], $element, explode(',', $page)))) {
     $query['page'] = $new_page;
   }
diff --git a/core/includes/path.inc b/core/includes/path.inc
index ba1da88d9c5968e6a08f37a3a2d8c887cd1a5f70..2187dd39e0bc047e59abd6cfba8ee94bd6c5caaf 100644
--- a/core/includes/path.inc
+++ b/core/includes/path.inc
@@ -22,7 +22,7 @@ function drupal_is_front_page() {
   $is_front_page = &$drupal_static_fast['is_front_page'];
 
   if (!isset($is_front_page)) {
-    $is_front_page = (current_path() == Drupal::config('system.site')->get('page.front'));
+    $is_front_page = (current_path() == \Drupal::config('system.site')->get('page.front'));
   }
 
   return $is_front_page;
@@ -53,7 +53,7 @@ function drupal_match_path($path, $patterns) {
     $replacements = array(
       '|',
       '.*',
-      '\1' . preg_quote(Drupal::config('system.site')->get('page.front'), '/') . '\2'
+      '\1' . preg_quote(\Drupal::config('system.site')->get('page.front'), '/') . '\2'
     );
     $patterns_quoted = preg_quote($patterns, '/');
     $regexps[$patterns] = '/^(' . preg_replace($to_replace, $replacements, $patterns_quoted) . ')$/';
@@ -158,7 +158,7 @@ function path_is_admin($path) {
 function path_get_admin_paths() {
   $patterns = &drupal_static(__FUNCTION__);
   if (!isset($patterns)) {
-    $paths = Drupal::moduleHandler()->invokeAll('admin_paths');
+    $paths = \Drupal::moduleHandler()->invokeAll('admin_paths');
     drupal_alter('admin_paths', $paths);
     // Combine all admin paths into one array, and likewise for non-admin paths,
     // for easier handling.
@@ -214,7 +214,7 @@ function drupal_valid_path($path, $dynamic_allowed = FALSE) {
   // Check the new routing system.
   if (!empty($item['route_name'])) {
     $map = array();
-    $route = Drupal::service('router.route_provider')->getRouteByName($item['route_name']);
+    $route = \Drupal::service('router.route_provider')->getRouteByName($item['route_name']);
     $item['access'] = menu_item_route_access($route, $path, $map);
   }
   $menu_admin = FALSE;
diff --git a/core/includes/schema.inc b/core/includes/schema.inc
index ac0ffadf6f383d2a61411d97098dc3b7b62dfd22..6563621c54717a32d09c2b7646b797031f66f4cf 100644
--- a/core/includes/schema.inc
+++ b/core/includes/schema.inc
@@ -77,11 +77,11 @@ function drupal_get_complete_schema($rebuild = FALSE) {
     else {
       $schema = array();
       // Load the .install files to get hook_schema.
-      Drupal::moduleHandler()->loadAllIncludes('install');
+      \Drupal::moduleHandler()->loadAllIncludes('install');
 
       require_once __DIR__ . '/common.inc';
       // Invoke hook_schema for all modules.
-      foreach (Drupal::moduleHandler()->getImplementations('schema') as $module) {
+      foreach (\Drupal::moduleHandler()->getImplementations('schema') as $module) {
         // Cast the result of hook_schema() to an array, as a NULL return value
         // would cause array_merge() to set the $schema variable to NULL as well.
         // That would break modules which use $schema further down the line.
@@ -121,7 +121,7 @@ function drupal_get_schema_versions($module) {
   $updates = &drupal_static(__FUNCTION__, NULL);
   if (!isset($updates[$module])) {
     $updates = array();
-    foreach (Drupal::moduleHandler()->getModuleList() as $loaded_module => $filename) {
+    foreach (\Drupal::moduleHandler()->getModuleList() as $loaded_module => $filename) {
       $updates[$loaded_module] = array();
     }
 
@@ -173,7 +173,7 @@ function drupal_get_installed_schema_version($module, $reset = FALSE, $array = F
   }
 
   if (!$versions) {
-    if (!$versions = Drupal::keyValue('system.schema')->getAll()) {
+    if (!$versions = \Drupal::keyValue('system.schema')->getAll()) {
       $versions = array();
     }
   }
@@ -195,7 +195,7 @@ function drupal_get_installed_schema_version($module, $reset = FALSE, $array = F
  *   The new schema version.
  */
 function drupal_set_installed_schema_version($module, $version) {
-  Drupal::keyValue('system.schema')->set($module, $version);
+  \Drupal::keyValue('system.schema')->set($module, $version);
   // Reset the static cache of module schema versions.
   drupal_get_installed_schema_version(NULL, TRUE);
 }
diff --git a/core/includes/session.inc b/core/includes/session.inc
index 0e01693cc9fb16b6c9d2137a3523faf65f85fe90..4cc81397e42a8835c9168db24d00687203654065 100644
--- a/core/includes/session.inc
+++ b/core/includes/session.inc
@@ -92,7 +92,7 @@ function _drupal_session_read($sid) {
   // client's session in the database. If it's HTTPS then we are either have
   // a HTTPS session or we are about to log in so we check the sessions table
   // for an anonymous session with the non-HTTPS-only cookie.
-  if (Drupal::request()->isSecure()) {
+  if (\Drupal::request()->isSecure()) {
     $values = db_query("SELECT u.*, s.* FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.ssid = :ssid", array(':ssid' => $sid))->fetchAssoc();
     if (!$values) {
       if (isset($_COOKIE[$insecure_session_name])) {
@@ -176,7 +176,7 @@ function _drupal_session_write($sid, $value) {
       // Either ssid or sid or both will be added from $key below.
       $fields = array(
         'uid' => $user->id(),
-        'hostname' => Drupal::request()->getClientIP(),
+        'hostname' => \Drupal::request()->getClientIP(),
         'session' => $value,
         'timestamp' => REQUEST_TIME,
       );
@@ -186,7 +186,7 @@ function _drupal_session_write($sid, $value) {
       // default.
       $key = array('sid' => $sid, 'ssid' => '');
       // On HTTPS connections, use the session ID as both 'sid' and 'ssid'.
-      if (Drupal::request()->isSecure()) {
+      if (\Drupal::request()->isSecure()) {
         $key['ssid'] = $sid;
         // The "secure pages" setting allows a site to simultaneously use both
         // secure and insecure session cookies. If enabled and both cookies are
@@ -240,7 +240,7 @@ function drupal_session_initialize() {
 
   session_set_save_handler('_drupal_session_open', '_drupal_session_close', '_drupal_session_read', '_drupal_session_write', '_drupal_session_destroy', '_drupal_session_garbage_collection');
 
-  $is_https = Drupal::request()->isSecure();
+  $is_https = \Drupal::request()->isSecure();
   // We use !empty() in the following check to ensure that blank session IDs
   // are not valid.
   if (!empty($_COOKIE[session_name()]) || ($is_https && settings()->get('mixed_mode_sessions', FALSE) && !empty($_COOKIE[substr(session_name(), 1)]))) {
@@ -319,7 +319,7 @@ function drupal_session_commit() {
     // started.
     if (!drupal_session_started()) {
       drupal_session_start();
-      if (Drupal::request()->isSecure() && settings()->get('mixed_mode_sessions', FALSE)) {
+      if (\Drupal::request()->isSecure() && settings()->get('mixed_mode_sessions', FALSE)) {
         $insecure_session_name = substr(session_name(), 1);
         $params = session_get_cookie_params();
         $expire = $params['lifetime'] ? REQUEST_TIME + $params['lifetime'] : 0;
@@ -355,7 +355,7 @@ function drupal_session_regenerate() {
     return;
   }
 
-  $is_https = Drupal::request()->isSecure();
+  $is_https = \Drupal::request()->isSecure();
 
   if ($is_https && settings()->get('mixed_mode_sessions', FALSE)) {
     $insecure_session_name = substr(session_name(), 1);
@@ -431,7 +431,7 @@ function _drupal_session_destroy($sid) {
     return;
   }
 
-  $is_https = Drupal::request()->isSecure();
+  $is_https = \Drupal::request()->isSecure();
   // Delete session data.
   db_delete('sessions')
     ->condition($is_https ? 'ssid' : 'sid', $sid)
@@ -461,7 +461,7 @@ function _drupal_session_destroy($sid) {
  *   Force the secure value of the cookie.
  */
 function _drupal_session_delete_cookie($name, $secure = NULL) {
-  if (isset($_COOKIE[$name]) || (!Drupal::request()->isSecure() && $secure === TRUE)) {
+  if (isset($_COOKIE[$name]) || (!\Drupal::request()->isSecure() && $secure === TRUE)) {
     $params = session_get_cookie_params();
     if ($secure !== NULL) {
       $params['secure'] = $secure;
diff --git a/core/includes/tablesort.inc b/core/includes/tablesort.inc
index 14da51c9a523327aeaecabf3e15a9b470c590fd5..1f6962bac3da6191f02535eae32a0db75000fddc 100644
--- a/core/includes/tablesort.inc
+++ b/core/includes/tablesort.inc
@@ -101,7 +101,7 @@ function tablesort_cell($cell, $header, $ts, $i) {
  *   page request except for those pertaining to table sorting.
  */
 function tablesort_get_query_parameters() {
-  return Url::filterQueryParameters(Drupal::request()->query->all(), array('sort', 'order'));
+  return Url::filterQueryParameters(\Drupal::request()->query->all(), array('sort', 'order'));
 }
 
 /**
@@ -116,7 +116,7 @@ function tablesort_get_query_parameters() {
  *   - "sql": The name of the database field to sort on.
  */
 function tablesort_get_order($headers) {
-  $order = Drupal::request()->query->get('order', '');
+  $order = \Drupal::request()->query->get('order', '');
   foreach ($headers as $header) {
     if (is_array($header)) {
       if (isset($header['data']) && $order == $header['data']) {
@@ -151,7 +151,7 @@ function tablesort_get_order($headers) {
  *   The current sort direction ("asc" or "desc").
  */
 function tablesort_get_sort($headers) {
-  $query = Drupal::request()->query;
+  $query = \Drupal::request()->query;
   if ($query->has('sort')) {
     return (strtolower($query->get('sort')) == 'desc') ? 'desc' : 'asc';
   }
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 5e12ff5a982390e746a8ebcd736bf09080328e21..6c240c7fa7e3bb0566b12691cd065ecb8dfce1b8 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -97,7 +97,7 @@ function drupal_theme_initialize() {
 
   // Only select the user selected theme if it is available in the
   // list of themes that can be accessed.
-  $theme = !empty($user->theme) && drupal_theme_access($user->theme) ? $user->theme : Drupal::config('system.theme')->get('default');
+  $theme = !empty($user->theme) && drupal_theme_access($user->theme) ? $user->theme : \Drupal::config('system.theme')->get('default');
 
   // Allow modules to override the theme. Validation has already been performed
   // inside menu_get_custom_theme(), so we do not need to check it again here.
@@ -372,14 +372,14 @@ function _theme_load_registry($theme, $base_theme = NULL, $theme_engine = NULL,
       $registry = _theme_build_registry($theme, $base_theme, $theme_engine);
       // Only persist this registry if all modules are loaded. This assures a
       // complete set of theme hooks.
-      if (Drupal::moduleHandler()->isLoaded()) {
+      if (\Drupal::moduleHandler()->isLoaded()) {
         _theme_save_registry($theme, $registry);
       }
     }
     return $registry;
   }
   else {
-    return new ThemeRegistry('theme_registry:runtime:' . $theme->name, 'cache', array('theme_registry' => TRUE), Drupal::moduleHandler()->isLoaded());
+    return new ThemeRegistry('theme_registry:runtime:' . $theme->name, 'cache', array('theme_registry' => TRUE), \Drupal::moduleHandler()->isLoaded());
   }
 }
 
@@ -457,7 +457,7 @@ function _theme_process_registry(&$cache, $name, $type, $theme, $path) {
     'base hook' => TRUE,
   );
 
-  $module_list = array_keys(Drupal::moduleHandler()->getModuleList());
+  $module_list = array_keys(\Drupal::moduleHandler()->getModuleList());
 
   // Invoke the hook_theme() implementation, preprocess what is returned, and
   // merge it into $cache.
@@ -610,11 +610,11 @@ function _theme_build_registry($theme, $base_theme, $theme_engine) {
     $cache = $cached->data;
   }
   else {
-    foreach (Drupal::moduleHandler()->getImplementations('theme') as $module) {
+    foreach (\Drupal::moduleHandler()->getImplementations('theme') as $module) {
       _theme_process_registry($cache, $module, 'module', $module, drupal_get_path('module', $module));
     }
     // Only cache this registry if all modules are loaded.
-    if (Drupal::moduleHandler()->isLoaded()) {
+    if (\Drupal::moduleHandler()->isLoaded()) {
       cache()->set("theme_registry:build:modules", $cache, CacheBackendInterface::CACHE_PERMANENT, array('theme_registry' => TRUE));
     }
   }
@@ -914,7 +914,7 @@ function theme($hook, $variables = array()) {
   // If called before all modules are loaded, we do not necessarily have a full
   // theme registry to work with, and therefore cannot process the theme
   // request properly. See also _theme_load_registry().
-  if (!Drupal::moduleHandler()->isLoaded() && !defined('MAINTENANCE_MODE')) {
+  if (!\Drupal::moduleHandler()->isLoaded() && !defined('MAINTENANCE_MODE')) {
     throw new Exception(t('theme() may not be called until all modules are loaded.'));
   }
 
@@ -1363,11 +1363,11 @@ function theme_get_setting($setting_name, $theme = NULL) {
     }
 
     // Get the global settings from configuration.
-    $cache[$theme]->mergeData(Drupal::config('system.theme.global')->get());
+    $cache[$theme]->mergeData(\Drupal::config('system.theme.global')->get());
 
     if ($theme) {
       // Get the saved theme-specific settings from the configuration system.
-      $cache[$theme]->mergeData(Drupal::config($theme . '.settings')->get());
+      $cache[$theme]->mergeData(\Drupal::config($theme . '.settings')->get());
 
       // If the theme does not support a particular feature, override the global
       // setting and set the value to NULL.
@@ -1464,8 +1464,8 @@ function theme_settings_convert_to_config(array $theme_settings, Config $config)
  */
 function theme_enable($theme_list) {
   drupal_clear_css_cache();
-  $theme_config = Drupal::config('system.theme');
-  $disabled_themes = Drupal::config('system.theme.disabled');
+  $theme_config = \Drupal::config('system.theme');
+  $disabled_themes = \Drupal::config('system.theme.disabled');
   foreach ($theme_list as $key) {
     // Throw an exception if the theme name is too long.
     if (strlen($key) > DRUPAL_EXTENSION_NAME_MAX_LENGTH) {
@@ -1486,12 +1486,12 @@ function theme_enable($theme_list) {
     config_install_default_config('theme', $key);
   }
 
-  Drupal::service('router.builder')->rebuild();
+  \Drupal::service('router.builder')->rebuild();
   menu_router_rebuild();
   drupal_theme_rebuild();
 
   // Invoke hook_themes_enabled() after the themes have been enabled.
-  Drupal::moduleHandler()->invokeAll('themes_enabled', array($theme_list));
+  \Drupal::moduleHandler()->invokeAll('themes_enabled', array($theme_list));
 }
 
 /**
@@ -1502,7 +1502,7 @@ function theme_enable($theme_list) {
  */
 function theme_disable($theme_list) {
   // Don't disable the default theme.
-  if ($pos = array_search(Drupal::config('system.theme')->get('default'), $theme_list) !== FALSE) {
+  if ($pos = array_search(\Drupal::config('system.theme')->get('default'), $theme_list) !== FALSE) {
     unset($theme_list[$pos]);
     if (empty($theme_list)) {
       return;
@@ -1511,8 +1511,8 @@ function theme_disable($theme_list) {
 
   drupal_clear_css_cache();
 
-  $theme_config = Drupal::config('system.theme');
-  $disabled_themes = Drupal::config('system.theme.disabled');
+  $theme_config = \Drupal::config('system.theme');
+  $disabled_themes = \Drupal::config('system.theme.disabled');
   foreach ($theme_list as $key) {
     // The value is not used; the weight is ignored for themes currently.
     $theme_config->clear("enabled.$key");
@@ -1522,12 +1522,12 @@ function theme_disable($theme_list) {
   $disabled_themes->save();
 
   list_themes(TRUE);
-  Drupal::service('router.builder')->rebuild();
+  \Drupal::service('router.builder')->rebuild();
   menu_router_rebuild();
   drupal_theme_rebuild();
 
   // Invoke hook_themes_disabled after the themes have been disabled.
-  Drupal::moduleHandler()->invokeAll('themes_disabled', array($theme_list));
+  \Drupal::moduleHandler()->invokeAll('themes_disabled', array($theme_list));
 }
 
 /**
@@ -2564,7 +2564,7 @@ function template_preprocess_html(&$variables) {
     drupal_add_html_head_link(array('rel' => 'shortcut icon', 'href' => drupal_strip_dangerous_protocols($favicon), 'type' => $type));
   }
 
-  $site_config = Drupal::config('system.site');
+  $site_config = \Drupal::config('system.site');
   // Construct page title.
   if (isset($variables['page']['#title'])) {
     $head_title = array(
@@ -2663,7 +2663,7 @@ function template_preprocess_html(&$variables) {
  */
 function template_preprocess_page(&$variables) {
   $language_interface = language(Language::TYPE_INTERFACE);
-  $site_config = Drupal::config('system.site');
+  $site_config = \Drupal::config('system.site');
 
   // Move some variables to the top level for themer convenience and template cleanliness.
   $variables['show_messages'] = $variables['page']['#show_messages'];
@@ -2866,7 +2866,7 @@ function template_preprocess_maintenance_page(&$variables) {
     $variables['layout'] = ($variables['layout'] == 'first') ? 'both' : 'second';
   }
 
-  $site_config = Drupal::config('system.site');
+  $site_config = \Drupal::config('system.site');
   $site_name = $site_config->get('name');
   $site_slogan = $site_config->get('slogan');
 
diff --git a/core/includes/theme.maintenance.inc b/core/includes/theme.maintenance.inc
index 5c35ac3b555159224d219ebc3bd130d772801cf0..5a22dd16f9b28b71c674fb04c3ab2a1ed4ee7927 100644
--- a/core/includes/theme.maintenance.inc
+++ b/core/includes/theme.maintenance.inc
@@ -54,7 +54,7 @@ function _drupal_maintenance_theme() {
     //   otherwise, as it looks generic enough and way more user-friendly.
     $custom_theme = variable_get('maintenance_theme');
     if (!$custom_theme)  {
-      $config = Drupal::config('system.theme');
+      $config = \Drupal::config('system.theme');
       // A broken install might not return an object.
       if (is_object($config)) {
         $custom_theme = $config->get('default');
@@ -68,7 +68,7 @@ function _drupal_maintenance_theme() {
   // Ensure that system.module is loaded.
   if (!function_exists('_system_rebuild_theme_data')) {
     $module_list['system'] = 'core/modules/system/system.module';
-    $module_handler = Drupal::moduleHandler();
+    $module_handler = \Drupal::moduleHandler();
     $module_handler->setModuleList($module_list);
     $module_handler->load('system');
   }
diff --git a/core/includes/update.inc b/core/includes/update.inc
index 0808cfc3ec07db60181d0eb428bbd62398c66548..a8c410960da0f155bc24d57cf595856bb6f7c8c0 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -32,7 +32,7 @@
  */
 function update_fix_compatibility() {
   foreach (array('module', 'theme') as $type) {
-    $config = Drupal::config("system.$type");
+    $config = \Drupal::config("system.$type");
     $save = FALSE;
     foreach ($config->get('enabled') as $name => $weight) {
       if (update_check_incompatibility($name, $type)) {
@@ -72,7 +72,7 @@ function update_check_incompatibility($name, $type = 'module') {
   }
   if (!isset($file)
       || !isset($file->info['core'])
-      || $file->info['core'] != Drupal::CORE_COMPATIBILITY
+      || $file->info['core'] != \Drupal::CORE_COMPATIBILITY
       || version_compare(phpversion(), $file->info['php']) < 0) {
     return TRUE;
   }
@@ -334,11 +334,11 @@ function update_prepare_d8_bootstrap() {
         variable_set('language_default', (array) $language_default);
       }
 
-      $module_config = Drupal::config('system.module');
-      $disabled_modules = Drupal::config('system.module.disabled');
-      $theme_config = Drupal::config('system.theme');
-      $disabled_themes = Drupal::config('system.theme.disabled');
-      $schema_store = Drupal::keyValue('system.schema');
+      $module_config = \Drupal::config('system.module');
+      $disabled_modules = \Drupal::config('system.module.disabled');
+      $theme_config = \Drupal::config('system.theme');
+      $disabled_themes = \Drupal::config('system.theme.disabled');
+      $schema_store = \Drupal::keyValue('system.schema');
 
       // Load system.module, because update_prepare_d8_bootstrap() is called in
       // the initial minimal update.php bootstrap that performs the core
@@ -398,7 +398,7 @@ function update_prepare_d8_bootstrap() {
       foreach (array_keys($sorted_modules) as $m) {
         $sorted_with_filenames[$m] = drupal_get_filename('module', $m);
       }
-      Drupal::moduleHandler()->setModuleList($sorted_with_filenames);
+      \Drupal::moduleHandler()->setModuleList($sorted_with_filenames);
       $disabled_modules->save();
       $theme_config->save();
       $disabled_themes->save();
@@ -416,7 +416,7 @@ function update_prepare_d8_bootstrap() {
       update_prepare_d8_language();
       // Rebuild kernel after new language fields are added in the database
       // because the translation service depends on them being there.
-      Drupal::service('kernel')->updateModules($sorted_with_filenames, $sorted_with_filenames);
+      \Drupal::service('kernel')->updateModules($sorted_with_filenames, $sorted_with_filenames);
 
       // Change language column to langcode in url_alias.
       if (db_table_exists('url_alias') && db_field_exists('url_alias', 'language')) {
@@ -444,7 +444,7 @@ function update_prepare_d8_bootstrap() {
   // directly. Check that it has not been set already. This is the case for
   // Simpletest upgrade path tests.
   if (!settings()->get('install_profile')) {
-    $old_variable = unserialize(Drupal::database()->query('SELECT value FROM {variable} WHERE name = :name', array(':name' => 'install_profile'))->fetchField());
+    $old_variable = unserialize(\Drupal::database()->query('SELECT value FROM {variable} WHERE name = :name', array(':name' => 'install_profile'))->fetchField());
     $settings = array(
       'settings' => array(
         'install_profile' => (object) array(
@@ -509,9 +509,9 @@ function update_prepare_d8_language() {
       $prefixes[$language->language] = $language->prefix;
       $domains[$language->language] = $language->domain;
     }
-    Drupal::state()->set('locale.translation.plurals', $plurals);
-    Drupal::state()->set('locale.translation.javascript', $javascript);
-    Drupal::config('language.negotiation')
+    \Drupal::state()->set('locale.translation.plurals', $plurals);
+    \Drupal::state()->set('locale.translation.javascript', $javascript);
+    \Drupal::config('language.negotiation')
       ->set('url.prefixes', $prefixes)
       ->set('url.domains', $domains)
       ->save();
@@ -526,7 +526,7 @@ function update_prepare_d8_language() {
     db_drop_field('languages', 'enabled');
 
     // Update language count.
-    Drupal::state()->set('language_count', db_query('SELECT COUNT(language) FROM {languages}')->fetchField());
+    \Drupal::state()->set('language_count', db_query('SELECT COUNT(language) FROM {languages}')->fetchField());
 
     // Rename the languages table to language.
     db_rename_table('languages', 'language');
@@ -590,7 +590,7 @@ function update_prepare_d8_language() {
     $result = db_query('SELECT * FROM {language}');
     $uuid = new Uuid();
     foreach ($result as $language) {
-      Drupal::config('language.entity.' . $language->langcode)
+      \Drupal::config('language.entity.' . $language->langcode)
         ->set('id', $language->langcode)
         ->set('uuid', $uuid->generate())
         ->set('label', $language->name)
@@ -727,7 +727,7 @@ function update_fix_d8_requirements() {
     // views configurations.
     // Like any other module APIs and services, Views' services are not available
     // in update.php. Existing listings are migrated into configuration, using
-    // the limited standard tools of raw database queries and Drupal::config().
+    // the limited standard tools of raw database queries and \Drupal::config().
     module_enable(array('views'));
 
     update_variable_set('update_d8_requirements', TRUE);
@@ -745,7 +745,7 @@ function update_fix_d8_requirements() {
  *   The schema version the module should be set to.
  */
 function update_set_schema($module, $schema_version) {
-  Drupal::keyValue('system.schema')->set($module, $schema_version);
+  \Drupal::keyValue('system.schema')->set($module, $schema_version);
   // system_list_reset() is in module.inc but that would only be available
   // once the variable bootstrap is done.
   require_once __DIR__ . '/module.inc';
@@ -875,13 +875,13 @@ function update_do_one($module, $number, $dependency_map, &$context) {
 function update_batch($start, $redirect = NULL, $url = NULL, $batch = array(), $redirect_callback = NULL) {
   // During the update, bring the site offline so that schema changes do not
   // affect visiting users.
-  $maintenance_mode = Drupal::config('system.maintenance')->get('enabled');
+  $maintenance_mode = \Drupal::config('system.maintenance')->get('enabled');
   if (isset($maintenance_mode)) {
     $_SESSION['maintenance_mode'] = $maintenance_mode;
   }
   if (empty($_SESSION['maintenance_mode'])) {
     if (db_table_exists('state')) {
-      Drupal::state()->set('system.maintenance_mode', TRUE);
+      \Drupal::state()->set('system.maintenance_mode', TRUE);
     }
   }
 
@@ -953,7 +953,7 @@ function update_finished($success, $results, $operations) {
   // Now that the update is done, we can put the site back online if it was
   // previously in maintenance mode.
   if (isset($_SESSION['maintenance_mode'])) {
-    Drupal::state()->set('system.maintenance_mode', FALSE);
+    \Drupal::state()->set('system.maintenance_mode', FALSE);
     unset($_SESSION['maintenance_mode']);
   }
 }
@@ -1273,7 +1273,7 @@ function update_retrieve_dependencies() {
   $return = array();
   // Get a list of installed modules, arranged so that we invoke their hooks in
   // the same order that \Drupal::moduleHandler()->invokeAll() does.
-  foreach (Drupal::keyValue('system.schema')->getAll() as $module => $schema) {
+  foreach (\Drupal::keyValue('system.schema')->getAll() as $module => $schema) {
     if ($schema == SCHEMA_UNINSTALLED) {
       // Nothing to upgrade.
       continue;
@@ -1417,7 +1417,7 @@ function update_variables_to_config($config_name, array $variable_map) {
   // Build the new configuration object.
   // This potentially loads an existing configuration object, in case another
   // update function migrated configuration values into $config_name already.
-  $config = Drupal::config($config_name);
+  $config = \Drupal::config($config_name);
   $original_data = $config->get();
 
   // Extract the module namespace/owner from the configuration object name.
@@ -1447,7 +1447,7 @@ function update_variables_to_config($config_name, array $variable_map) {
     // This function migrates variables regardless of their value, including
     // NULL values. Any possibly required customizations need to be performed
     // manually, either via variable_set() before calling this function or via
-    // Drupal::config() after calling this function.
+    // \Drupal::config() after calling this function.
     if (isset($variables[$variable_name])) {
       $value = unserialize($variables[$variable_name]);
       $config->set($config_key, $value);
@@ -1481,7 +1481,7 @@ function update_variables_to_config($config_name, array $variable_map) {
  */
 function update_install_default_config($type, $config_name, $name = NULL) {
   // Build the new configuration object.
-  $config = Drupal::config($config_name);
+  $config = \Drupal::config($config_name);
 
   // Extract the extension namespace/owner from the configuration object name.
   if (!$name) {
@@ -1503,7 +1503,7 @@ function update_install_default_config($type, $config_name, $name = NULL) {
  * Updates 7.x variables to state records.
  *
  * Provides a generalized method to migrate variables from 7.x to 8.x's
- * Drupal::state() system.
+ * \Drupal::state() system.
  *
  * @param array $variable_map
  *   An associative array that maps old variables names to new state record
@@ -1518,7 +1518,7 @@ function update_install_default_config($type, $config_name, $name = NULL) {
 function update_variables_to_state(array $variable_map) {
   foreach ($variable_map as $variable_name => $state_name) {
     if (NULL !== $value = update_variable_get($variable_name)) {
-      Drupal::state()->set($state_name, $value);
+      \Drupal::state()->set($state_name, $value);
     }
   }
 
@@ -1599,10 +1599,10 @@ function update_add_cache_columns($table) {
 function update_replace_permissions($replace) {
   $prefix = 'user.role.';
   $cut = strlen($prefix);
-  $role_names = Drupal::service('config.storage')->listAll($prefix);
+  $role_names = \Drupal::service('config.storage')->listAll($prefix);
   foreach ($role_names as $role_name) {
     $rid = substr($role_name, $cut);
-    $config = Drupal::config("user.role.$rid");
+    $config = \Drupal::config("user.role.$rid");
     $permissions = $config->get('permissions') ?: array();
     foreach ($replace as $old_permission => $new_permissions) {
       if (($index = array_search($old_permission, $permissions)) !== FALSE) {
@@ -1648,7 +1648,7 @@ function update_language_list($flags = Language::STATE_CONFIGURABLE) {
       // save the same object without data loss.
       foreach ($language_entities as $langcode_config_name) {
         $langcode = substr($langcode_config_name, strlen('language.entity.'));
-        $info = Drupal::config($langcode_config_name)->get();
+        $info = \Drupal::config($langcode_config_name)->get();
         $languages[$langcode] = new Language(array(
           'default' => ($info['id'] == $default->id),
           'name' => $info['label'],
diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index f29523294f3c42e26ae7073669039a08326ae74d..0d100df2e3008a0fc2ca91f81350cf545a484392 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -37,21 +37,21 @@
  *
  *   // Correct procedural code.
  *   function hook_do_stuff() {
- *     $lock = Drupal::lock()->acquire('stuff_lock');
+ *     $lock = \Drupal::lock()->acquire('stuff_lock');
  *     // ...
  *   }
  *
  *   // The preferred way: dependency injected code.
  *   function hook_do_stuff() {
  *     // Move the actual implementation to a class and instantiate it.
- *     $instance = new StuffDoingClass(Drupal::lock());
+ *     $instance = new StuffDoingClass(\Drupal::lock());
  *     $instance->doStuff();
  *
  *     // Or, even better, rely on the service container to avoid hard coding a
  *     // specific interface implementation, so that the actual logic can be
  *     // swapped. This might not always make sense, but in general it is a good
  *     // practice.
- *     Drupal::service('stuff.doing')->doStuff();
+ *     \Drupal::service('stuff.doing')->doStuff();
  *   }
  *
  *   interface StuffDoingInterface {
@@ -455,7 +455,7 @@ public static function linkGenerator() {
    * However, for links enclosed in translatable text you should use t() and
    * embed the HTML anchor tag directly in the translated string. For example:
    * @code
-   * t('Visit the <a href="@url">content types</a> page', array('@url' => Drupal::url('node.overview_types')));
+   * t('Visit the <a href="@url">content types</a> page', array('@url' => \Drupal::url('node.overview_types')));
    * @endcode
    * This keeps the context of the link title ('settings' in the example) for
    * translators.
diff --git a/core/lib/Drupal/Core/Entity/DatabaseStorageController.php b/core/lib/Drupal/Core/Entity/DatabaseStorageController.php
index c016093f6e499c1ddce40e57d6f0bfed3d142791..3ab46aa0a46ff9f919665c78ef20220bb1528378 100644
--- a/core/lib/Drupal/Core/Entity/DatabaseStorageController.php
+++ b/core/lib/Drupal/Core/Entity/DatabaseStorageController.php
@@ -1094,7 +1094,7 @@ static public function _fieldTableName(FieldInterface $field) {
    * @private Calling this function circumvents the entity system and is
    * strongly discouraged. This function is not considered part of the public
    * API and modules relying on it might break even in minor releases. Only
-   * call this function to write a query that Drupal::entityQuery() does not
+   * call this function to write a query that \Drupal::entityQuery() does not
    * support. Always call entity_load() before using the data found in the
    * table.
    *
diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index 98b486404a38666ed5a4554ef32492b180a856d0..67e5690f82a1bdf2f50777f54fa2fef87e0105c9 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -374,7 +374,7 @@ protected function getController($entity_type, $controller_type) {
    *   langcode. Defaults to an empty array.
    * @code
    *   $form_state['langcode'] = $langcode;
-   *   $manager = Drupal::entityManager();
+   *   $manager = \Drupal::entityManager();
    *   $form = $manager->getForm($entity, 'default', $form_state);
    * @endcode
    *
diff --git a/core/lib/Drupal/Core/Entity/Query/QueryInterface.php b/core/lib/Drupal/Core/Entity/Query/QueryInterface.php
index 3a02e8e4d82c8cd3cfbd593923046a01522afabf..3c2682c6de2812353ca68621a6d72b87c96ff804 100644
--- a/core/lib/Drupal/Core/Entity/Query/QueryInterface.php
+++ b/core/lib/Drupal/Core/Entity/Query/QueryInterface.php
@@ -38,7 +38,7 @@ public function getEntityType();
    * For example, to find all entities containing both the Turkish 'merhaba'
    * and the Polish 'siema' within a 'greetings' text field:
    * @code
-   *   $entity_ids = Drupal::entityQuery($entity_type)
+   *   $entity_ids = \Drupal::entityQuery($entity_type)
    *     ->condition('greetings', 'merhaba', '=', 'tr');
    *     ->condition('greetings.value', 'siema', '=', 'pl');
    *     ->execute();
@@ -186,7 +186,7 @@ public function execute();
    * field containing 'shape' and 'color' columns. To find all drawings
    * containing both a red triangle and a blue circle:
    * @code
-   *   $query = Drupal::entityQuery('drawing');
+   *   $query = \Drupal::entityQuery('drawing');
    *   $group = $query->andConditionGroup()
    *     ->condition('figures.color', 'red')
    *     ->condition('figures.shape', 'triangle');
@@ -209,7 +209,7 @@ public function andConditionGroup();
    * containing 'building_type' and 'color' columns.  To find all green and
    * red bikesheds:
    * @code
-   *   $query = Drupal::entityQuery('map');
+   *   $query = \Drupal::entityQuery('map');
    *   $group = $query->orConditionGroup()
    *     ->condition('attributes.color', 'red')
    *     ->condition('attributes.color', 'green');
diff --git a/core/lib/Drupal/Core/Extension/CachedModuleHandler.php b/core/lib/Drupal/Core/Extension/CachedModuleHandler.php
index 295cead8fbce57b0d7c3147cc2587dee356faa74..6e0943209a50f42b81ae730f869acdf4ee79c583 100644
--- a/core/lib/Drupal/Core/Extension/CachedModuleHandler.php
+++ b/core/lib/Drupal/Core/Extension/CachedModuleHandler.php
@@ -81,7 +81,7 @@ public function resetImplementations() {
     // $this->bootstrapCache->get() is more or less constant and reduced further when
     // non-database caching backends are used, so there will be more significant
     // gains when a large number of modules are installed or hooks invoked, since
-    // this can quickly lead to Drupal::moduleHandler()->implementsHook() being
+    // this can quickly lead to \Drupal::moduleHandler()->implementsHook() being
     // called several thousand times per request.
     parent::resetImplementations();
     $this->bootstrapCache->set('module_implements', array());
@@ -121,7 +121,7 @@ protected function getImplementationInfo($hook) {
         // It is possible that a module removed a hook implementation without the
         // implementations cache being rebuilt yet, so we check whether the
         // function exists on each request to avoid undefined function errors.
-        // Since Drupal::moduleHandler()->implementsHook() may needlessly try to
+        // Since \Drupal::moduleHandler()->implementsHook() may needlessly try to
         // load the include file again, function_exists() is used directly here.
         if (!function_exists($module . '_' . $hook)) {
           // Clear out the stale implementation from the cache and force a cache
diff --git a/core/lib/Drupal/Core/Utility/LinkGeneratorInterface.php b/core/lib/Drupal/Core/Utility/LinkGeneratorInterface.php
index a85262fc5ecacda389b859b101fc22603a6c8425..965eed2017384696de9a5bd8d272cb00ce52a906 100644
--- a/core/lib/Drupal/Core/Utility/LinkGeneratorInterface.php
+++ b/core/lib/Drupal/Core/Utility/LinkGeneratorInterface.php
@@ -22,7 +22,7 @@ interface LinkGeneratorInterface {
    * However, for links enclosed in translatable text you should use t() and
    * embed the HTML anchor tag directly in the translated string. For example:
    * @code
-   * t('Visit the <a href="@url">content types</a> page', array('@url' => Drupal::url('node.overview_types')));
+   * t('Visit the <a href="@url">content types</a> page', array('@url' => \Drupal::url('node.overview_types')));
    * @endcode
    * This keeps the context of the link title ('settings' in the example) for
    * translators.
diff --git a/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
index 0edf99687501fef502025fee7a378d18d788a735..1534cb3004c17e59ec79f42b7d7123fd9244baa8 100644
--- a/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -246,7 +246,7 @@ function aggregator_cron() {
     ':time' => REQUEST_TIME,
     ':never' => AGGREGATOR_CLEAR_NEVER
   ));
-  $queue = Drupal::queue('aggregator_feeds');
+  $queue = \Drupal::queue('aggregator_feeds');
   foreach ($result->fetchCol() as $fid) {
     $feed = aggregator_feed_load($fid);
     if ($queue->createItem($feed)) {
@@ -302,7 +302,7 @@ function aggregator_save_category($edit) {
         ->condition('cid', $edit['cid'])
         ->execute();
       // Make sure there is no active block for this category.
-      if (Drupal::moduleHandler()->moduleExists('block')) {
+      if (\Drupal::moduleHandler()->moduleExists('block')) {
         foreach (entity_load_multiple_by_properties('block', array('plugin' => 'aggregator_category_block:' . $edit['cid'])) as $block) {
           $block->delete();
         }
@@ -322,7 +322,7 @@ function aggregator_save_category($edit) {
       ->execute();
     $op = 'insert';
   }
-  if (isset($op) && Drupal::moduleHandler()->moduleExists('menu_link')) {
+  if (isset($op) && \Drupal::moduleHandler()->moduleExists('menu_link')) {
     menu_link_maintain('aggregator', $op, $link_path, $edit['title']);
   }
 }
@@ -337,9 +337,9 @@ function aggregator_refresh(Feed $feed) {
   // Store feed URL to track changes.
   $feed_url = $feed->url->value;
 
-  $config = Drupal::config('aggregator.settings');
+  $config = \Drupal::config('aggregator.settings');
   // Fetch the feed.
-  $fetcher_manager = Drupal::service('plugin.manager.aggregator.fetcher');
+  $fetcher_manager = \Drupal::service('plugin.manager.aggregator.fetcher');
   try {
     $success = $fetcher_manager->createInstance($config->get('fetcher'))->fetch($feed);
   }
@@ -349,7 +349,7 @@ function aggregator_refresh(Feed $feed) {
   }
 
   // Retrieve processor manager now.
-  $processor_manager = Drupal::service('plugin.manager.aggregator.processor');
+  $processor_manager = \Drupal::service('plugin.manager.aggregator.processor');
   // Store instances in an array so we dont have to instantiate new objects.
   $processor_instances = array();
   foreach ($config->get('processors') as $processor) {
@@ -368,7 +368,7 @@ function aggregator_refresh(Feed $feed) {
 
   if ($success && ($feed->hash->value != $hash)) {
     // Parse the feed.
-    $parser_manager = Drupal::service('plugin.manager.aggregator.parser');
+    $parser_manager = \Drupal::service('plugin.manager.aggregator.parser');
     try {
       if ($parser_manager->createInstance($config->get('parser'))->parse($feed)) {
         if (empty($feed->link->value)) {
@@ -439,7 +439,7 @@ function aggregator_feed_load($fid) {
  *   instead.
  */
 function aggregator_category_load($cid) {
-  return Drupal::service('aggregator.category.storage')->load($cid);
+  return \Drupal::service('aggregator.category.storage')->load($cid);
 }
 
 /**
@@ -467,7 +467,7 @@ function theme_aggregator_block_item($variables) {
  *   The filtered content.
  */
 function aggregator_filter_xss($value) {
-  return filter_xss($value, preg_split('/\s+|<|>/', Drupal::config('aggregator.settings')->get('items.allowed_html'), -1, PREG_SPLIT_NO_EMPTY));
+  return filter_xss($value, preg_split('/\s+|<|>/', \Drupal::config('aggregator.settings')->get('items.allowed_html'), -1, PREG_SPLIT_NO_EMPTY));
 }
 
 /**
diff --git a/core/modules/aggregator/aggregator.pages.inc b/core/modules/aggregator/aggregator.pages.inc
index 2a8e5f7114ae562911e845a7da3e28bce3093604..57e2b5ca322aafd93ab28101f2f4ebd7d0f1ace4 100644
--- a/core/modules/aggregator/aggregator.pages.inc
+++ b/core/modules/aggregator/aggregator.pages.inc
@@ -37,7 +37,7 @@
  *   An array of the feed items.
  */
 function aggregator_load_feed_items($type, $data = NULL, $limit = 20) {
-  $storage_controller = Drupal::entityManager()->getStorageController('aggregator_item');
+  $storage_controller = \Drupal::entityManager()->getStorageController('aggregator_item');
   switch ($type) {
     case 'sum':
       return $storage_controller->loadAll($limit);
@@ -148,7 +148,7 @@ function theme_aggregator_page_opml($variables) {
   $output  = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
   $output .= "<opml version=\"1.1\">\n";
   $output .= "<head>\n";
-  $output .= '<title>' . check_plain(Drupal::config('system.site')->get('name')) . "</title>\n";
+  $output .= '<title>' . check_plain(\Drupal::config('system.site')->get('name')) . "</title>\n";
   $output .= '<dateModified>' . gmdate(DATE_RFC2822, REQUEST_TIME) . "</dateModified>\n";
   $output .= "</head>\n";
   $output .= "<body>\n";
diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index 843a7a728fea98110f4991a18ad6f6aef603aac2..5fd66cb514d567fd63928660f6892f9173df3d73 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -56,7 +56,7 @@ function block_help($path, $arg) {
       $demo_theme = $arg[4];
     }
     else {
-      $demo_theme = Drupal::config('system.theme')->get('default');
+      $demo_theme = \Drupal::config('system.theme')->get('default');
     }
     $themes = list_themes();
     $output = '<p>' . t('This page provides a drag-and-drop interface for adding a block to a region, and for controlling the order of blocks within regions. To add a block to a region, or to configure its specific title and visibility settings, click the block title under <em>Place blocks</em>. Since not all themes implement the same regions, or display regions in the same way, blocks are positioned on a per-theme basis. Remember that your changes will not be saved until you click the <em>Save blocks</em> button at the bottom of the page.') . '</p>';
@@ -98,7 +98,7 @@ function block_permission() {
  * @todo Clarify the documentation for the per-plugin block admin links.
  */
 function block_menu() {
-  $default_theme = Drupal::config('system.theme')->get('default');
+  $default_theme = \Drupal::config('system.theme')->get('default');
   $items['admin/structure/block'] = array(
     'title' => 'Block layout',
     'description' => 'Configure what block content appears in your site\'s sidebars and other regions.',
@@ -236,7 +236,7 @@ function block_page_build(&$page) {
     $page['page_top']['backlink'] = array(
       '#type' => 'link',
       '#title' => t('Exit block region demonstration'),
-      '#href' => 'admin/structure/block' . (Drupal::config('system.theme')->get('default') == $theme ? '' : '/list/' . $theme),
+      '#href' => 'admin/structure/block' . (\Drupal::config('system.theme')->get('default') == $theme ? '' : '/list/' . $theme),
       // Add the "overlay-restore" class to indicate this link should restore
       // the context in which the region demonstration page was opened.
       '#options' => array('attributes' => array('class' => array('block-demo-backlink', 'overlay-restore'))),
@@ -279,9 +279,9 @@ function _block_get_renderable_region($list = array()) {
   // the regular 'roles define permissions' schema, it brings too many
   // chances of having unwanted output get in the cache and later be served
   // to other users. We therefore exclude user 1 from block caching.
-  $not_cacheable = Drupal::currentUser()->id() == 1 ||
-    count(Drupal::moduleHandler()->getImplementations('node_grants')) ||
-    !Drupal::request()->isMethodSafe();
+  $not_cacheable = \Drupal::currentUser()->id() == 1 ||
+    count(\Drupal::moduleHandler()->getImplementations('node_grants')) ||
+    !\Drupal::request()->isMethodSafe();
 
   foreach ($list as $key => $block) {
     $settings = $block->get('settings');
@@ -336,7 +336,7 @@ function _block_get_renderable_region($list = array()) {
  *   Blocks currently exported by modules.
  */
 function _block_rehash($theme = NULL) {
-  $theme = $theme ? $theme : Drupal::config('system.theme')->get('default');
+  $theme = $theme ? $theme : \Drupal::config('system.theme')->get('default');
   $regions = system_region_list($theme);
   $blocks = entity_load_multiple_by_properties('block', array('theme' => $theme));
   foreach ($blocks as $block_id => $block) {
@@ -385,7 +385,7 @@ function block_theme_initialize($theme) {
   // Initialize theme's blocks if none already registered.
   $has_blocks = entity_load_multiple_by_properties('block', array('theme' => $theme));
   if (!$has_blocks) {
-    $default_theme = Drupal::config('system.theme')->get('default');
+    $default_theme = \Drupal::config('system.theme')->get('default');
     // Apply only to new theme's visible regions.
     $regions = system_region_list($theme, REGIONS_VISIBLE);
     $default_theme_blocks = entity_load_multiple_by_properties('block', array('theme' => $default_theme));
@@ -615,7 +615,7 @@ function block_language_delete($language) {
 function block_library_info() {
   $libraries['drupal.block'] = array(
     'title' => 'Block',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'block') . '/block.js' => array(),
     ),
@@ -626,7 +626,7 @@ function block_library_info() {
   );
   $libraries['drupal.block.admin'] = array(
     'title' => 'Block admin',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'block') . '/js/block.admin.js' => array(),
     ),
diff --git a/core/modules/block/custom_block/custom_block.module b/core/modules/block/custom_block/custom_block.module
index e938f88b464bb25dcee7bdfd943ba066c23dbfa8..20460ce8180c27722325e846d9a53ab6a86789cb 100644
--- a/core/modules/block/custom_block/custom_block.module
+++ b/core/modules/block/custom_block/custom_block.module
@@ -189,7 +189,7 @@ function custom_block_entity_info_alter(&$types) {
 function custom_block_entity_bundle_info() {
   $bundles = array();
   foreach (config_get_storage_names_with_prefix('custom_block.type.') as $config_name) {
-    $config = Drupal::config($config_name);
+    $config = \Drupal::config($config_name);
     $bundles['custom_block'][$config->get('id')]['label'] = $config->get('label');
   }
   return $bundles;
diff --git a/core/modules/block/custom_block/custom_block.pages.inc b/core/modules/block/custom_block/custom_block.pages.inc
index b6d080c490491305922017f38bcdb6e109f6f08a..4cca4cc71601314e16e2d4dfe7e9a93924a73252 100644
--- a/core/modules/block/custom_block/custom_block.pages.inc
+++ b/core/modules/block/custom_block/custom_block.pages.inc
@@ -22,10 +22,10 @@
  */
 function template_preprocess_custom_block_add_list(&$variables) {
   $variables['types'] = array();
-  $query = Drupal::request()->query->all();
+  $query = \Drupal::request()->query->all();
   foreach ($variables['content'] as $type) {
     $variables['types'][$type->id()] = array(
-      'link' => Drupal::l($type->label(), 'custom_block.add_form', array('custom_block_type' => $type->id()), array('query' => $query)),
+      'link' => \Drupal::l($type->label(), 'custom_block.add_form', array('custom_block_type' => $type->id()), array('query' => $query)),
       'description' => filter_xss_admin($type->description),
       'title' => $type->label(),
       'localized_options' => array(
diff --git a/core/modules/block/tests/modules/block_test/block_test.module b/core/modules/block/tests/modules/block_test/block_test.module
index 5184454dee04e1c9c76b2dd14298d7499f116177..437020295df137ae3ba3c45788bb3992f897906a 100644
--- a/core/modules/block/tests/modules/block_test/block_test.module
+++ b/core/modules/block/tests/modules/block_test/block_test.module
@@ -17,7 +17,7 @@ function block_test_system_theme_info() {
  * Implements hook_block_alter().
  */
 function block_test_block_alter(&$block_info) {
-  if (Drupal::state()->get('block_test_info_alter') && isset($block_info['test_block_instantiation'])) {
+  if (\Drupal::state()->get('block_test_info_alter') && isset($block_info['test_block_instantiation'])) {
     $block_info['test_block_instantiation']['category'] = t('Custom category');
   }
 }
diff --git a/core/modules/book/book.admin.inc b/core/modules/book/book.admin.inc
index 09261f2f613a576831abed08be3f10784282e80b..1d7061b6c540bb0f8bf67228dedace6c1c7909a8 100644
--- a/core/modules/book/book.admin.inc
+++ b/core/modules/book/book.admin.inc
@@ -29,7 +29,7 @@ function theme_book_admin_table($variables) {
 
   $rows = array();
   $destination = drupal_get_destination();
-  $access = Drupal::currentUser()->hasPermission('administer nodes');
+  $access = \Drupal::currentUser()->hasPermission('administer nodes');
   foreach (element_children($form) as $key) {
     $nid = $form[$key]['nid']['#value'];
     $href = $form[$key]['href']['#value'];
diff --git a/core/modules/book/book.install b/core/modules/book/book.install
index 786a1cffacfe82941f66037bbb37ad11c7232437..fb8c225815f9a7ffdbce7afeeaaf05b1a002adc8 100644
--- a/core/modules/book/book.install
+++ b/core/modules/book/book.install
@@ -73,7 +73,7 @@ function book_update_8000() {
     // @see book_admin_settings_submit()
     sort($allowed_types);
 
-    Drupal::config('book.settings')
+    \Drupal::config('book.settings')
       ->set('allowed_types', $allowed_types)
       ->save();
   }
diff --git a/core/modules/book/book.module b/core/modules/book/book.module
index 8ed85c4d3f2d04e33422ef4b04500030e5695d9a..1039b599d51f19ef2386bf99f6ccbcccf6d05005 100644
--- a/core/modules/book/book.module
+++ b/core/modules/book/book.module
@@ -130,11 +130,11 @@ function book_entity_info(&$entity_info) {
  */
 function book_node_view_link(NodeInterface $node, $view_mode) {
   $links = array();
-  $account = Drupal::currentUser();
+  $account = \Drupal::currentUser();
 
   if (isset($node->book['depth'])) {
     if ($view_mode == 'full' && node_is_page($node)) {
-      $child_type = Drupal::config('book.settings')->get('child_type');
+      $child_type = \Drupal::config('book.settings')->get('child_type');
       if (($account->hasPermission('add content to books') || $account->hasPermission('administer book outlines')) && node_access('create', $child_type) && $node->isPublished() && $node->book['depth'] < MENU_MAX_DEPTH) {
         $links['book_add_child'] = array(
           'title' => t('Add child page'),
@@ -218,7 +218,7 @@ function book_menu() {
  * @see book_menu()
  */
 function _book_outline_access(EntityInterface $node) {
-  return Drupal::currentUser()->hasPermission('administer book outlines') && node_access('view', $node);
+  return \Drupal::currentUser()->hasPermission('administer book outlines') && node_access('view', $node);
 }
 
 /**
@@ -230,7 +230,7 @@ function _book_outline_access(EntityInterface $node) {
  * @see book_menu()
  */
 function _book_outline_remove_access(EntityInterface $node) {
-  return Drupal::service('book.manager')->checkNodeIsRemovable($node)
+  return \Drupal::service('book.manager')->checkNodeIsRemovable($node)
     && _book_outline_access($node);
 }
 
@@ -238,7 +238,7 @@ function _book_outline_remove_access(EntityInterface $node) {
  * Implements hook_admin_paths().
  */
 function book_admin_paths() {
-  if (Drupal::config('node.settings')->get('use_admin_theme')) {
+  if (\Drupal::config('node.settings')->get('use_admin_theme')) {
     $paths = array(
       'node/*/outline' => TRUE,
       'node/*/outline/remove' => TRUE,
@@ -259,7 +259,7 @@ function book_admin_paths() {
  *   An array of all books.
  */
 function book_get_books() {
-  return Drupal::service('book.manager')->getAllBooks();
+  return \Drupal::service('book.manager')->getAllBooks();
 }
 
 /**
@@ -271,7 +271,7 @@ function book_get_books() {
  */
 function book_form_node_form_alter(&$form, &$form_state, $form_id) {
   $node = $form_state['controller']->getEntity();
-  $account = Drupal::currentUser();
+  $account = \Drupal::currentUser();
   $access = $account->hasPermission('administer book outlines');
   if (!$access) {
     if ($account->hasPermission('add content to books') && ((!empty($node->book['mlid']) && !$node->isNew()) || book_type_is_allowed($node->getType()))) {
@@ -281,7 +281,7 @@ function book_form_node_form_alter(&$form, &$form_state, $form_id) {
   }
 
   if ($access) {
-    $form = Drupal::service('book.manager')->addFormElements($form, $form_state, $node, $account);
+    $form = \Drupal::service('book.manager')->addFormElements($form, $form_state, $node, $account);
     // Since the "Book" dropdown can't trigger a form submission when
     // JavaScript is disabled, add a submit button to do that. book.admin.css hides
     // this button when JavaScript is enabled.
@@ -541,7 +541,7 @@ function book_page_alter(&$page) {
  */
 function book_node_presave(EntityInterface $node) {
   // Always save a revision for non-administrators.
-  if (!empty($node->book['bid']) && !Drupal::currentUser()->hasPermission('administer nodes')) {
+  if (!empty($node->book['bid']) && !\Drupal::currentUser()->hasPermission('administer nodes')) {
     $node->setNewRevision();
   }
   // Make sure a new node gets a new menu link.
@@ -554,7 +554,7 @@ function book_node_presave(EntityInterface $node) {
  * Implements hook_node_insert().
  */
 function book_node_insert(EntityInterface $node) {
-  $book_manager = Drupal::service('book.manager');
+  $book_manager = \Drupal::service('book.manager');
   if (!empty($node->book['bid'])) {
     if ($node->book['bid'] == 'new') {
       // New nodes that are their own book.
@@ -570,7 +570,7 @@ function book_node_insert(EntityInterface $node) {
  * Implements hook_node_update().
  */
 function book_node_update(EntityInterface $node) {
-  $book_manager = Drupal::service('book.manager');
+  $book_manager = \Drupal::service('book.manager');
   if (!empty($node->book['bid'])) {
     if ($node->book['bid'] == 'new') {
       // New nodes that are their own book.
@@ -595,7 +595,7 @@ function book_node_predelete(EntityInterface $node) {
       foreach ($result as $child) {
         $child_node = node_load($child->id());
         $child_node->book['bid'] = $child_node->id();
-        Drupal::service('book.manager')->updateOutline($child_node);
+        \Drupal::service('book.manager')->updateOutline($child_node);
       }
     }
     menu_link_delete($node->book['mlid']);
@@ -611,10 +611,10 @@ function book_node_predelete(EntityInterface $node) {
  */
 function book_node_prepare_form(NodeInterface $node, $form_display, $operation, array &$form_state) {
   // Get BookManager service
-  $book_manager = Drupal::service('book.manager');
+  $book_manager = \Drupal::service('book.manager');
 
   // Prepare defaults for the add/edit form.
-  $account = Drupal::currentUser();
+  $account = \Drupal::currentUser();
   if (empty($node->book) && ($account->hasPermission('add content to books') || $account->hasPermission('administer book outlines'))) {
     $node->book = array();
 
@@ -809,7 +809,7 @@ function template_preprocess_book_node_export_html(&$variables) {
  *   A Boolean TRUE if the node type can be included in books; otherwise, FALSE.
  */
 function book_type_is_allowed($type) {
-  return in_array($type, Drupal::config('book.settings')->get('allowed_types'));
+  return in_array($type, \Drupal::config('book.settings')->get('allowed_types'));
 }
 
 /**
@@ -820,7 +820,7 @@ function book_type_is_allowed($type) {
  */
 function book_node_type_update(NodeTypeInterface $type) {
   if ($type->getOriginalID() != $type->id()) {
-    $config = Drupal::config('book.settings');
+    $config = \Drupal::config('book.settings');
     // Update the list of node types that are allowed to be added to books.
     $allowed_types = $config->get('allowed_types');
     $old_key = array_search($type->getOriginalID(), $allowed_types);
@@ -937,7 +937,7 @@ function book_menu_subtree_data($link) {
 function book_library_info() {
   $libraries['drupal.book'] = array(
     'title' => 'Book',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'book') . '/book.js' => array(),
     ),
diff --git a/core/modules/book/book.pages.inc b/core/modules/book/book.pages.inc
index 40e44b2b7cab95cc8b7260b0ceaf7b12172fdba0..fe4c6a0a496e59a74c0a64652ab6a2226592cc35 100644
--- a/core/modules/book/book.pages.inc
+++ b/core/modules/book/book.pages.inc
@@ -50,7 +50,7 @@ function book_remove_form($form, &$form_state, EntityInterface $node) {
  */
 function book_remove_form_submit($form, &$form_state) {
   $node = $form['#node'];
-  if (Drupal::service('book.manager')->checkNodeIsRemovable($node)) {
+  if (\Drupal::service('book.manager')->checkNodeIsRemovable($node)) {
     menu_link_delete($node->book['mlid']);
     db_delete('book')
       ->condition('nid', $node->id())
diff --git a/core/modules/breakpoint/breakpoint.install b/core/modules/breakpoint/breakpoint.install
index 6c74779f922dd7592baaa3f97d598125823aab14..1dc28fd094287f52acdfd45049880cf331f9f822 100644
--- a/core/modules/breakpoint/breakpoint.install
+++ b/core/modules/breakpoint/breakpoint.install
@@ -16,5 +16,5 @@ function breakpoint_enable() {
   _breakpoint_theme_enabled(array_keys($themes));
 
   // Import breakpoints from modules.
-  _breakpoint_modules_enabled(array_keys(Drupal::moduleHandler()->getModuleList()));
+  _breakpoint_modules_enabled(array_keys(\Drupal::moduleHandler()->getModuleList()));
 }
diff --git a/core/modules/breakpoint/breakpoint.module b/core/modules/breakpoint/breakpoint.module
index 1a4a80c0cb120e9349ea8c334652140e0d38d296..31fa932ac00eed7af537da63deadabb70e23d228 100644
--- a/core/modules/breakpoint/breakpoint.module
+++ b/core/modules/breakpoint/breakpoint.module
@@ -156,7 +156,7 @@ function _breakpoint_import_media_queries($group_name, $label, $source_type, $me
  *   Either Breakpoint::SOURCE_TYPE_THEME or Breakpoint::SOURCE_TYPE_MODULE.
  */
 function _breakpoint_import_breakpoint_groups($source, $source_type) {
-  $breakpoint_groups = Drupal::config($source . '.breakpoint_groups');
+  $breakpoint_groups = \Drupal::config($source . '.breakpoint_groups');
   if ($breakpoint_groups) {
     foreach ($breakpoint_groups->get() as $group_name => $data) {
       // Breakpoints is mandatory, extra check since this is coming from config.
@@ -188,7 +188,7 @@ function _breakpoint_import_breakpoint_groups($source, $source_type) {
  */
 function _breakpoint_delete_breakpoints($list, $source_type) {
   $ids = config_get_storage_names_with_prefix('breakpoint.breakpoint_group.' . $source_type . '.');
-  $entity_info = Drupal::service('entity.manager')->getDefinition('breakpoint_group');
+  $entity_info = \Drupal::service('entity.manager')->getDefinition('breakpoint_group');
 
   // Remove the breakpoint.breakpoint part of the breakpoint identifier.
   foreach ($ids as &$id) {
@@ -202,8 +202,8 @@ function _breakpoint_delete_breakpoints($list, $source_type) {
       $breakpoint_group->delete();
 
       // Get all breakpoints defined by this theme/module.
-      $breakpoint_ids = Drupal::service('config.storage')->listAll('breakpoint.breakpoint.' . $source_type . '.' . $breakpoint_group->id() . '.');
-      $entity_info = Drupal::service('entity.manager')->getDefinition('breakpoint');
+      $breakpoint_ids = \Drupal::service('config.storage')->listAll('breakpoint.breakpoint.' . $source_type . '.' . $breakpoint_group->id() . '.');
+      $entity_info = \Drupal::service('entity.manager')->getDefinition('breakpoint');
 
       // Remove the breakpoint.breakpoint part of the breakpoint identifier.
       foreach ($breakpoint_ids as &$breakpoint_id) {
@@ -260,7 +260,7 @@ function breakpoint_get_theme_media_queries($theme_key) {
     throw new \Exception('Illegal theme_key passed.');
   }
 
-  $config = Drupal::config($theme_key . '.breakpoints');
+  $config = \Drupal::config($theme_key . '.breakpoints');
   if ($config) {
     return $config->get();
   }
@@ -277,11 +277,11 @@ function breakpoint_get_theme_media_queries($theme_key) {
  *   An array of breakpoints in the form $breakpoint['name'] = 'media query'.
  */
 function breakpoint_get_module_media_queries($module) {
-  if (!Drupal::moduleHandler()->moduleExists($module)) {
+  if (!\Drupal::moduleHandler()->moduleExists($module)) {
     throw new \Exception('Illegal module name passed.');
   }
 
-  $config = Drupal::config($module . '.breakpoints');
+  $config = \Drupal::config($module . '.breakpoints');
   if ($config) {
     return $config->get();
   }
diff --git a/core/modules/ckeditor/ckeditor.module b/core/modules/ckeditor/ckeditor.module
index 10f8bab6324585a87e0c06037d6d3c8dd0452e4a..aceb3a81b7a35e582ca6782466a13f48459790a1 100644
--- a/core/modules/ckeditor/ckeditor.module
+++ b/core/modules/ckeditor/ckeditor.module
@@ -44,7 +44,7 @@ function ckeditor_library_info() {
   );
   $libraries['drupal.ckeditor'] = array(
     'title' => 'Drupal behavior to enable CKEditor on textareas.',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $module_path . '/js/ckeditor.js' => array(),
       array('data' => $settings, 'type' => 'setting'),
@@ -60,7 +60,7 @@ function ckeditor_library_info() {
   );
   $libraries['drupal.ckeditor.admin'] = array(
     'title' => 'Drupal behavior for drag-and-drop CKEditor toolbar builder UI.',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $module_path . '/js/ckeditor.admin.js' => array(),
     ),
@@ -83,7 +83,7 @@ function ckeditor_library_info() {
   );
   $libraries['drupal.ckeditor.drupalimage.admin'] = array(
     'title' => 'Only show the "drupalimage" plugin settings when its button is enabled.',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $module_path . '/js/ckeditor.drupalimage.admin.js' => array(),
     ),
@@ -97,7 +97,7 @@ function ckeditor_library_info() {
   );
   $libraries['drupal.ckeditor.stylescombo.admin'] = array(
     'title' => 'Only show the "stylescombo" plugin settings when its button is enabled.',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $module_path . '/js/ckeditor.stylescombo.admin.js' => array(),
     ),
@@ -111,7 +111,7 @@ function ckeditor_library_info() {
   );
   $libraries['drupal.ckeditor.drupalimagecaption-theme'] = array(
     'title' => 'Theming support for the imagecaption plugin.',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $module_path . '/js/plugins/drupalimagecaption/theme.js' => array(),
     ),
@@ -176,7 +176,7 @@ function ckeditor_ckeditor_css_alter(array &$css, Editor $editor) {
 function _ckeditor_theme_css($theme = NULL) {
   $css = array();
   if (!isset($theme)) {
-    $theme = Drupal::config('system.theme')->get('default');
+    $theme = \Drupal::config('system.theme')->get('default');
   }
   if ($theme_path = drupal_get_path('theme', $theme)) {
     $info = system_get_info('theme', $theme);
diff --git a/core/modules/color/color.install b/core/modules/color/color.install
index f896938c3ae6b98963ac30884cc4603af0b8e50c..923f38f0c91817db7254848b8ccf27ffd874b2c5 100644
--- a/core/modules/color/color.install
+++ b/core/modules/color/color.install
@@ -52,7 +52,7 @@ function color_update_8001() {
     // Get theme name from color palette variable.
     preg_match('/color_(.*)_palette/', $theme_palette, $matches);
     $theme_key = $matches[1];
-    $config = Drupal::config('color.' . $theme_key);
+    $config = \Drupal::config('color.' . $theme_key);
     $config->set('palette', update_variable_get('color_' . $theme_key . '_palette'));
     $config->set('logo', update_variable_get('color_' . $theme_key . '_logo'));
     $config->set('stylesheets', update_variable_get('color_' . $theme_key . '_stylesheets'));
diff --git a/core/modules/color/color.module b/core/modules/color/color.module
index fefb51ae404cecaa212a63f7857a07a1136cd005..8cc622343283fd3b5d9aa239ffbac6eea0284ee2 100644
--- a/core/modules/color/color.module
+++ b/core/modules/color/color.module
@@ -64,7 +64,7 @@ function color_css_alter(&$css) {
   $themes = list_themes();
 
   // Override stylesheets.
-  $color_paths = Drupal::config('color.' . $theme_key)->get('stylesheets');
+  $color_paths = \Drupal::config('color.' . $theme_key)->get('stylesheets');
 
   if (!empty($color_paths) && !empty($themes[$theme_key]->stylesheets['all'])) {
 
@@ -93,7 +93,7 @@ function color_preprocess_page(&$variables) {
   global $theme_key;
 
   // Override logo.
-  $logo = Drupal::config('color.' . $theme_key)->get('logo');
+  $logo = \Drupal::config('color.' . $theme_key)->get('logo');
   if ($logo && $variables['logo'] && preg_match('!' . $theme_key . '/logo.png$!', $variables['logo'])) {
     $variables['logo'] = file_create_url($logo);
   }
@@ -132,7 +132,7 @@ function color_get_palette($theme, $default = FALSE) {
 
   // Load variable.
   // @todo Default color config should be moved to yaml in the theme.
-  return Drupal::config('color.' . $theme)->get('palette') ?: $palette;
+  return \Drupal::config('color.' . $theme)->get('palette') ?: $palette;
 }
 
 /**
@@ -160,7 +160,7 @@ function color_scheme_form($complete_form, &$form_state, $theme) {
 
   // See if we're using a predefined scheme.
   // Note: we use the original theme when the default scheme is chosen.
-  $current_scheme = Drupal::config('color.' . $theme)->get('palette');
+  $current_scheme = \Drupal::config('color.' . $theme)->get('palette');
   foreach ($schemes as $key => $scheme) {
     if ($current_scheme == $scheme) {
       $scheme_name = $key;
@@ -282,7 +282,7 @@ function color_scheme_form_submit($form, &$form_state) {
   $theme = $form_state['values']['theme'];
   $info = $form_state['values']['info'];
 
-  $config = Drupal::config('color.' . $theme);
+  $config = \Drupal::config('color.' . $theme);
 
   // Resolve palette.
   $palette = $form_state['values']['palette'];
@@ -540,7 +540,7 @@ function _color_render_images($theme, &$info, &$paths, $palette) {
     if ($file == 'screenshot.png') {
       $slice = imagecreatetruecolor(150, 90);
       imagecopyresampled($slice, $target, 0, 0, $x, $y, 150, 90, $width, $height);
-      Drupal::config('color.' . $theme)
+      \Drupal::config('color.' . $theme)
         ->set('screenshot', $image)
         ->save();
     }
@@ -736,7 +736,7 @@ function _color_rgb2hsl($rgb) {
 function color_library_info() {
   $libraries['drupal.color'] = array(
     'title' => 'Color',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'color') . '/color.js' => array(),
     ),
@@ -750,7 +750,7 @@ function color_library_info() {
   );
   $libraries['drupal.color.preview'] = array(
     'title' => 'Color preview',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'color') . '/preview.js' => array(),
     ),
diff --git a/core/modules/comment/comment.admin.inc b/core/modules/comment/comment.admin.inc
index 741ad5ce706808f1decadb840115a4bad0e9af58..f732a57969c5dd11a645f431f1bfa349f77105d5 100644
--- a/core/modules/comment/comment.admin.inc
+++ b/core/modules/comment/comment.admin.inc
@@ -18,11 +18,11 @@
  * @see comment_multiple_delete_confirm()
  */
 function comment_admin($type = 'new') {
-  $request = Drupal::request();
+  $request = \Drupal::request();
   $edit = $request->request->all();
 
   if (isset($edit['operation']) && ($edit['operation'] == 'delete') && isset($edit['comments']) && $edit['comments']) {
-    return drupal_get_form(ConfirmDeleteMultiple::create(Drupal::getContainer()), $request);
+    return drupal_get_form(ConfirmDeleteMultiple::create(\Drupal::getContainer()), $request);
   }
   else {
     return drupal_get_form('comment_admin_overview', $type);
diff --git a/core/modules/comment/comment.install b/core/modules/comment/comment.install
index 04e129175089378f27b25e92f6e6fb7e29b0f34e..f71a7e47d167c4497a508e9ecb047eeccbf52533 100644
--- a/core/modules/comment/comment.install
+++ b/core/modules/comment/comment.install
@@ -12,7 +12,7 @@ function comment_uninstall() {
   // Remove variables.
   variable_del('comment_block_count');
   $node_types = array_keys(node_type_get_types());
-  Drupal::entityManager()->addNamespaces(new ArrayIterator(array(
+  \Drupal::entityManager()->addNamespaces(new ArrayIterator(array(
     'Drupal\comment' => DRUPAL_ROOT . '/core/modules/comment/lib',
   )));
   drupal_classloader_register('comment', 'core/modules/comment');
@@ -30,7 +30,7 @@ function comment_uninstall() {
   }
 
   // Remove states.
-  Drupal::state()->delete('comment.node_comment_statistics_scale');
+  \Drupal::state()->delete('comment.node_comment_statistics_scale');
 }
 
 /**
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 45af84a90bced800eda9d9ca9c809ad8ef324638..64fe92b1814573b1e32ebb8e25bc96b85e13b129 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -525,7 +525,7 @@ function comment_node_view(EntityInterface $node, EntityDisplay $display, $view_
             'fragment' => 'comments',
             'html' => TRUE,
           );
-          if (Drupal::moduleHandler()->moduleExists('history')) {
+          if (\Drupal::moduleHandler()->moduleExists('history')) {
             $links['comment-new-comments'] = array(
               'title' => '',
               'href' => '',
@@ -604,7 +604,7 @@ function comment_node_view(EntityInterface $node, EntityDisplay $display, $view_
       '#links' => $links,
       '#attributes' => array('class' => array('links', 'inline')),
     );
-    if ($view_mode == 'teaser' && Drupal::moduleHandler()->moduleExists('history')) {
+    if ($view_mode == 'teaser' && \Drupal::moduleHandler()->moduleExists('history')) {
       $node->content['links']['#attached']['library'][] = array('comment', 'drupal.node-new-comments-link');
     }
 
@@ -622,7 +622,7 @@ function comment_node_view(EntityInterface $node, EntityDisplay $display, $view_
  * Implements hook_node_view_alter().
  */
 function comment_node_view_alter(&$build, EntityInterface $node, EntityDisplay $display) {
-  if (Drupal::moduleHandler()->moduleExists('history')) {
+  if (\Drupal::moduleHandler()->moduleExists('history')) {
     $build['#attributes']['data-history-node-id'] = $node->id();
   }
 }
@@ -687,7 +687,7 @@ function comment_node_page_additions(EntityInterface $node) {
 function comment_add(EntityInterface $node, $pid = NULL) {
   $values = array('nid' => $node->id(), 'pid' => $pid, 'node_type' => 'comment_node_' . $node->getType());
   $comment = entity_create('comment', $values);
-  return Drupal::entityManager()->getForm($comment);
+  return \Drupal::entityManager()->getForm($comment);
 }
 
 /**
@@ -1186,7 +1186,7 @@ function comment_node_update_index(EntityInterface $node, $langcode) {
     // edit could change the security situation so it is not safe to index the
     // comments.
     $index_comments = TRUE;
-    $roles = Drupal::entityManager()->getStorageController('user_role')->loadMultiple();
+    $roles = \Drupal::entityManager()->getStorageController('user_role')->loadMultiple();
     $authenticated_can_access = $roles[DRUPAL_AUTHENTICATED_RID]->hasPermission('access comments');
     foreach ($roles as $rid => $role) {
       if ($role->hasPermission('search content') && !$role->hasPermission('access comments')) {
@@ -1216,7 +1216,7 @@ function comment_node_update_index(EntityInterface $node, $langcode) {
  */
 function comment_update_index() {
   // Store the maximum possible comments per thread (used for ranking by reply count)
-  Drupal::state()->set('comment.node_comment_statistics_scale', 1.0 / max(1, db_query('SELECT MAX(comment_count) FROM {node_comment_statistics}')->fetchField()));
+  \Drupal::state()->set('comment.node_comment_statistics_scale', 1.0 / max(1, db_query('SELECT MAX(comment_count) FROM {node_comment_statistics}')->fetchField()));
 }
 
 /**
@@ -1423,7 +1423,7 @@ function comment_preview(Comment $comment) {
       $comment->name->value = check_plain($account->getUsername());
     }
     elseif (empty($comment->name->value)) {
-      $comment->name->value = Drupal::config('user.settings')->get('anonymous');
+      $comment->name->value = \Drupal::config('user.settings')->get('anonymous');
     }
 
     $comment->created->value = !empty($comment->created->value) ? $comment->created->value : REQUEST_TIME;
@@ -1521,7 +1521,7 @@ function template_preprocess_comment(&$variables) {
     $variables['user_picture'] = array();
   }
 
-  if (Drupal::config('user.settings')->get('signatures') && $account->getSignature()) {
+  if (\Drupal::config('user.settings')->get('signatures') && $account->getSignature()) {
     $variables['signature'] = check_markup($account->getSignature(), $account->getSignatureFormat(), '', TRUE) ;
   }
   else {
@@ -1646,7 +1646,7 @@ function theme_comment_post_forbidden($variables) {
         $destination = array('destination' => 'node/' . $node->id() . '#comment-form');
       }
 
-      if (Drupal::config('user.settings')->get('register') != USER_REGISTER_ADMINISTRATORS_ONLY) {
+      if (\Drupal::config('user.settings')->get('register') != USER_REGISTER_ADMINISTRATORS_ONLY) {
         // Users can register themselves.
         return t('<a href="@login">Log in</a> or <a href="@register">register</a> to post comments', array('@login' => url('user/login', array('query' => $destination)), '@register' => url('user/register', array('query' => $destination))));
       }
@@ -1750,7 +1750,7 @@ function comment_ranking() {
       ),
       // Inverse law that maps the highest reply count on the site to 1 and 0 to 0.
       'score' => '2.0 - 2.0 / (1.0 + node_comment_statistics.comment_count * CAST(:scale AS DECIMAL))',
-      'arguments' => array(':scale' => Drupal::state()->get('comment.node_comment_statistics_scale') ?: 0),
+      'arguments' => array(':scale' => \Drupal::state()->get('comment.node_comment_statistics_scale') ?: 0),
     ),
   );
 }
@@ -1775,7 +1775,7 @@ function comment_library_info() {
   $path = drupal_get_path('module', 'comment');
   $libraries['drupal.comment'] = array(
     'title' => 'Comment',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/comment-node-form.js' => array(),
     ),
@@ -1787,7 +1787,7 @@ function comment_library_info() {
   );
   $libraries['drupal.comment-by-viewer'] = array(
     'title' => 'Annotate comments by the current viewer for targeted styling',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/comment-by-viewer.js' => array(),
     ),
@@ -1799,7 +1799,7 @@ function comment_library_info() {
   );
   $libraries['drupal.comment-new-indicator'] = array(
     'title' => 'New comment indicator',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/comment-new-indicator.js' => array(),
     ),
@@ -1812,7 +1812,7 @@ function comment_library_info() {
   );
   $libraries['drupal.node-new-comments-link'] = array(
     'title' => 'New comments link',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/node-new-comments-link.js' => array(),
     ),
diff --git a/core/modules/comment/comment.tokens.inc b/core/modules/comment/comment.tokens.inc
index 80021628f5fe6e9abfd39a43d0ce323fac0ac631..da28f1a7dd1118d6fac019cee3c7e49cafdc497d 100644
--- a/core/modules/comment/comment.tokens.inc
+++ b/core/modules/comment/comment.tokens.inc
@@ -103,7 +103,7 @@ function comment_token_info() {
  * Implements hook_tokens().
  */
 function comment_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $url_options = array('absolute' => TRUE);
   if (isset($options['langcode'])) {
@@ -133,7 +133,7 @@ function comment_tokens($type, $tokens, array $data = array(), array $options =
           break;
 
         case 'name':
-          $name = ($comment->uid->target_id == 0) ? Drupal::config('user.settings')->get('anonymous') : $comment->name->value;
+          $name = ($comment->uid->target_id == 0) ? \Drupal::config('user.settings')->get('anonymous') : $comment->name->value;
           $replacements[$original] = $sanitize ? filter_xss($name) : $name;
           break;
 
diff --git a/core/modules/comment/comment.views.inc b/core/modules/comment/comment.views.inc
index d8887ffa18b71f991fda1ea0b1d925743d79e911..79602d2f702e04f8b5a053d38f426ccfb9a4059c 100644
--- a/core/modules/comment/comment.views.inc
+++ b/core/modules/comment/comment.views.inc
@@ -360,7 +360,7 @@ function comment_views_data() {
     ),
   );
 
-  if (Drupal::moduleHandler()->moduleExists('content_translation')) {
+  if (\Drupal::moduleHandler()->moduleExists('content_translation')) {
     $data['comment']['translation_link'] = array(
       'title' => t('Translation link'),
       'help' => t('Provide a link to the translations overview for comments.'),
diff --git a/core/modules/config/tests/config_test/config_test.module b/core/modules/config/tests/config_test/config_test.module
index c0cab7a332204864dd98b37a69f2b1634d28c75c..557224775e905dc5964d6a3bcb2c266443f9561b 100644
--- a/core/modules/config/tests/config_test/config_test.module
+++ b/core/modules/config/tests/config_test/config_test.module
@@ -79,7 +79,7 @@ function config_test_cache_flush() {
  * Implements hook_ENTITY_TYPE_create().
  */
 function config_test_config_test_create(ConfigTest $config_test) {
-  if (Drupal::state()->get('config_test.prepopulate')) {
+  if (\Drupal::state()->get('config_test.prepopulate')) {
     $config_test->set('foo', 'baz');
   }
 }
@@ -91,7 +91,7 @@ function config_test_entity_info_alter(&$entity_info) {
   // The 'translatable' entity key is not supposed to change over time. In this
   // case we can safely do it because we set it once and we do not change it for
   // all the duration of the test session.
-  $entity_info['config_test']['translatable'] = Drupal::service('state')->get('config_test.translatable');
+  $entity_info['config_test']['translatable'] = \Drupal::service('state')->get('config_test.translatable');
 
   // Create a clone of config_test that does not have a status.
   $entity_info['config_test_no_status'] = $entity_info['config_test'];
diff --git a/core/modules/contact/contact.install b/core/modules/contact/contact.install
index 60b51b01713cd571826009e688d683dfe689f320..3f71a5d9322ea531d3169d9af1f53203742f567d 100644
--- a/core/modules/contact/contact.install
+++ b/core/modules/contact/contact.install
@@ -12,11 +12,11 @@
  * Implements hook_install().
  */
 function contact_install() {
-  $site_mail = Drupal::config('system.site')->get('mail');
+  $site_mail = \Drupal::config('system.site')->get('mail');
   if (empty($site_mail)) {
     $site_mail = ini_get('sendmail_from');
   }
-  Drupal::config('contact.category.feedback')->set('recipients', array($site_mail))->save();
+  \Drupal::config('contact.category.feedback')->set('recipients', array($site_mail))->save();
 }
 
 /**
@@ -61,12 +61,12 @@ function contact_update_8001() {
     $category->id = $category->cid;
     // Save default category setting.
     if ($category->selected) {
-      Drupal::config('contact.settings')
+      \Drupal::config('contact.settings')
         ->set('default_category', $category->id)
         ->save();
     }
     // Save the config object.
-    Drupal::config('contact.category.' . $category->id)
+    \Drupal::config('contact.category.' . $category->id)
       ->set('id', $category->id)
       ->set('uuid', $uuid->generate())
       ->set('label', $category->category)
diff --git a/core/modules/contact/contact.module b/core/modules/contact/contact.module
index 673a50067aa24e5fce0ea42a84fea04904e36496..18180f8db77541739183d1864f983041fd245e0e 100644
--- a/core/modules/contact/contact.module
+++ b/core/modules/contact/contact.module
@@ -148,13 +148,13 @@ function _contact_personal_tab_access(UserInterface $account) {
 
   // If the requested user has disabled their contact form, do not allow users
   // to contact them.
-  $account_data = Drupal::service('user.data')->get('contact', $account->id(), 'enabled');
+  $account_data = \Drupal::service('user.data')->get('contact', $account->id(), 'enabled');
   if (isset($account_data) && empty($account_data)) {
     return FALSE;
   }
   // If the requested user did not save a preference yet, deny access if the
   // configured default is disabled.
-  elseif (!Drupal::config('contact.settings')->get('user_default_enabled')) {
+  elseif (!\Drupal::config('contact.settings')->get('user_default_enabled')) {
     return FALSE;
   }
 
@@ -167,7 +167,7 @@ function _contact_personal_tab_access(UserInterface $account) {
 function contact_entity_bundle_info() {
   $bundles = array();
   foreach (config_get_storage_names_with_prefix('contact.category.') as $config_name) {
-    $config = Drupal::config($config_name);
+    $config = \Drupal::config($config_name);
     $bundles['contact_message'][$config->get('id')]['label'] = $config->get('label');
   }
   return $bundles;
@@ -264,7 +264,7 @@ function contact_mail($key, &$message, $params) {
   $language = language_load($message['langcode']);
 
   $variables = array(
-    '!site-name' => Drupal::config('system.site')->get('name'),
+    '!site-name' => \Drupal::config('system.site')->get('name'),
     '!subject' => $contact_message->getSubject(),
     '!category' => !empty($params['contact_category']) ? $params['contact_category']->label() : NULL,
     '!form-url' => url(current_path(), array('absolute' => TRUE, 'language' => $language)),
@@ -324,11 +324,11 @@ function contact_form_user_form_alter(&$form, &$form_state) {
     '#weight' => 5,
   );
   $account = $form_state['controller']->getEntity();
-  $account_data = !user_is_anonymous() ? Drupal::service('user.data')->get('contact', $account->id(), 'enabled') : NULL;
+  $account_data = !user_is_anonymous() ? \Drupal::service('user.data')->get('contact', $account->id(), 'enabled') : NULL;
   $form['contact']['contact'] = array(
     '#type' => 'checkbox',
     '#title' => t('Personal contact form'),
-    '#default_value' => isset($account_data) ? $account_data : Drupal::config('contact.settings')->get('user_default_enabled'),
+    '#default_value' => isset($account_data) ? $account_data : \Drupal::config('contact.settings')->get('user_default_enabled'),
     '#description' => t('Allow other users to contact you via a personal contact form which keeps your e-mail address hidden. Note that some privileged users such as site administrators are still able to contact you even if you choose to disable this feature.'),
   );
   $form['actions']['submit']['#submit'][] = 'contact_user_profile_form_submit';
@@ -340,7 +340,7 @@ function contact_form_user_form_alter(&$form, &$form_state) {
 function contact_user_profile_form_submit($form, &$form_state) {
   $account = $form_state['controller']->getEntity();
   if ($account->id() && isset($form_state['values']['contact'])) {
-    Drupal::service('user.data')->set('contact', $account->id(), 'enabled', (int) $form_state['values']['contact']);
+    \Drupal::service('user.data')->set('contact', $account->id(), 'enabled', (int) $form_state['values']['contact']);
   }
 }
 
@@ -361,7 +361,7 @@ function contact_form_user_admin_settings_alter(&$form, &$form_state) {
     '#type' => 'checkbox',
     '#title' => t('Enable the personal contact form by default for new users.'),
     '#description' => t('Changing this setting will not affect existing users.'),
-    '#default_value' => Drupal::config('contact.settings')->get('user_default_enabled'),
+    '#default_value' => \Drupal::config('contact.settings')->get('user_default_enabled'),
   );
   // Add submit handler to save contact configuration.
   $form['#submit'][] = 'contact_form_user_admin_settings_submit';
@@ -373,7 +373,7 @@ function contact_form_user_admin_settings_alter(&$form, &$form_state) {
  * @see contact_form_user_admin_settings_alter()
  */
 function contact_form_user_admin_settings_submit($form, &$form_state) {
-  Drupal::config('contact.settings')
+  \Drupal::config('contact.settings')
     ->set('user_default_enabled', $form_state['values']['contact_default_status'])
     ->save();
 }
diff --git a/core/modules/contact/contact.pages.inc b/core/modules/contact/contact.pages.inc
index b6da2ec5a76e68554f4ef01ebb3c93bbca095e2b..5a8cea387474234a28e1c16c3f0359047ba6d06a 100644
--- a/core/modules/contact/contact.pages.inc
+++ b/core/modules/contact/contact.pages.inc
@@ -30,7 +30,7 @@ function contact_site_page(Category $category = NULL) {
 
   if (!isset($category)) {
     $categories = entity_load_multiple('contact_category');
-    $default_category = Drupal::config('contact.settings')->get('default_category');
+    $default_category = \Drupal::config('contact.settings')->get('default_category');
     if (isset($categories[$default_category])) {
       $category = $categories[$default_category];
     }
@@ -51,7 +51,7 @@ function contact_site_page(Category $category = NULL) {
   $message = entity_create('contact_message', array(
     'category' => $category->id(),
   ));
-  return Drupal::entityManager()->getForm($message);
+  return \Drupal::entityManager()->getForm($message);
 }
 
 /**
@@ -81,7 +81,7 @@ function contact_personal_page($recipient) {
     'recipient' => $recipient,
     'category' => 'personal',
   ));
-  return Drupal::entityManager()->getForm($message);
+  return \Drupal::entityManager()->getForm($message);
 }
 
 /**
@@ -93,10 +93,10 @@ function contact_personal_page($recipient) {
  * @see contact_personal_page()
  */
 function contact_flood_control() {
-  $config = Drupal::config('contact.settings');
+  $config = \Drupal::config('contact.settings');
   $limit = $config->get('flood.limit');
   $interval = $config->get('flood.interval');
-  if (!Drupal::service('flood')->isAllowed('contact', $limit, $interval)) {
+  if (!\Drupal::service('flood')->isAllowed('contact', $limit, $interval)) {
     drupal_set_message(t("You cannot send more than %limit messages in @interval. Try again later.", array(
       '%limit' => $limit,
       '@interval' => format_interval($interval),
diff --git a/core/modules/content_translation/content_translation.admin.inc b/core/modules/content_translation/content_translation.admin.inc
index da4558a374e87d0281606aee947d8131b69941b9..9904ba0dc3f8b6a22544002bb0311fd9ddab8794 100644
--- a/core/modules/content_translation/content_translation.admin.inc
+++ b/core/modules/content_translation/content_translation.admin.inc
@@ -424,7 +424,7 @@ function content_translation_translatable_batch($translatable, $field_name, &$co
       $query_field = "$field_name.$column";
 
       // How many entities will need processing?
-      $query = Drupal::entityQuery($entity_type);
+      $query = \Drupal::entityQuery($entity_type);
       $count = $query
         ->exists($query_field)
         ->count()
@@ -449,7 +449,7 @@ function content_translation_translatable_batch($translatable, $field_name, &$co
 
     $info = entity_get_info($entity_type);
     $offset = $context['sandbox']['progress_entity_type'][$entity_type];
-    $query = Drupal::entityQuery($entity_type);
+    $query = \Drupal::entityQuery($entity_type);
     $field = field_info_field($entity_type, $field_name);
     $column = isset($field['columns']['value']) ? 'value' : key($field['columns']);
     $query_field = "$field_name.$column";
diff --git a/core/modules/content_translation/content_translation.module b/core/modules/content_translation/content_translation.module
index 49a3adc2d14719ca4663806af7131b7227776678..1ccef25ad99597cdffd01506ef01e29199e6c5c8 100644
--- a/core/modules/content_translation/content_translation.module
+++ b/core/modules/content_translation/content_translation.module
@@ -356,7 +356,7 @@ function content_translation_library_info() {
   $path = drupal_get_path('module', 'content_translation');
   $libraries['drupal.content_translation.admin'] = array(
     'title' => 'Content translation UI',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/content_translation.admin.js' => array(),
     ),
@@ -413,7 +413,7 @@ function content_translation_get_config_key($entity_type, $bundle, $setting) {
  */
 function content_translation_get_config($entity_type, $bundle, $setting) {
   $key = content_translation_get_config_key($entity_type, $bundle, $setting);
-  return Drupal::config('content_translation.settings')->get($key);
+  return \Drupal::config('content_translation.settings')->get($key);
 }
 
 /**
@@ -430,7 +430,7 @@ function content_translation_get_config($entity_type, $bundle, $setting) {
  */
 function content_translation_set_config($entity_type, $bundle, $setting, $value) {
   $key = content_translation_get_config_key($entity_type, $bundle, $setting);
-  return Drupal::config('content_translation.settings')->set($key, $value)->save();
+  return \Drupal::config('content_translation.settings')->set($key, $value)->save();
 }
 
 /**
@@ -871,8 +871,8 @@ function content_translation_entity_presave(EntityInterface $entity) {
   if ($entity->isTranslatable()) {
     // @todo Avoid using request attributes once translation metadata become
     //   regular fields.
-    $attributes = Drupal::request()->attributes;
-    Drupal::service('content_translation.synchronizer')->synchronizeFields($entity, $entity->language()->id, $attributes->get('source_langcode'));
+    $attributes = \Drupal::request()->attributes;
+    \Drupal::service('content_translation.synchronizer')->synchronizeFields($entity, $entity->language()->id, $attributes->get('source_langcode'));
   }
 }
 
diff --git a/core/modules/content_translation/content_translation.pages.inc b/core/modules/content_translation/content_translation.pages.inc
index 966d259ee55d57b18281ab3e1c65c9f3e430c29e..f918c2be111e13b50f8ee680981e50634446f4ec 100644
--- a/core/modules/content_translation/content_translation.pages.inc
+++ b/core/modules/content_translation/content_translation.pages.inc
@@ -17,7 +17,7 @@
  */
 function content_translation_overview(EntityInterface $entity) {
   $controller = content_translation_controller($entity->entityType());
-  $entity_manager = Drupal::entityManager();
+  $entity_manager = \Drupal::entityManager();
   $languages = language_list();
   $original = $entity->getUntranslated()->language()->id;
   $translations = $entity->getTranslationLanguages();
@@ -201,7 +201,7 @@ function content_translation_add_page(EntityInterface $entity, Language $source
   $form_state['content_translation']['target'] = $target;
   $controller = content_translation_controller($entity->entityType());
   $form_state['content_translation']['translation_form'] = !$entity->access('update');
-  return Drupal::entityManager()->getForm($entity, $operation, $form_state);
+  return \Drupal::entityManager()->getForm($entity, $operation, $form_state);
 }
 
 /**
@@ -222,7 +222,7 @@ function content_translation_edit_page(EntityInterface $entity, Language $langua
   $operation = isset($info['default_operation']) ? $info['default_operation'] : 'default';
   $form_state['langcode'] = $language->id;
   $form_state['content_translation']['translation_form'] = TRUE;
-  return Drupal::entityManager()->getForm($entity, $operation, $form_state);
+  return \Drupal::entityManager()->getForm($entity, $operation, $form_state);
 }
 
 /**
@@ -287,7 +287,7 @@ function content_translation_delete_confirm_submit(array $form, array &$form_sta
   // @todo This should be taken care of by the Path module.
   if (module_exists('path')) {
     $conditions = array('source' => $controller->getViewPath($entity), 'langcode' => $language->id);
-    Drupal::service('path.crud')->delete($conditions);
+    \Drupal::service('path.crud')->delete($conditions);
   }
 
   $form_state['redirect'] = $controller->getBasePath($entity) . '/translations';
diff --git a/core/modules/contextual/contextual.module b/core/modules/contextual/contextual.module
index 70ed7ff5868dd700294450bb0a2fa2e24cd21405..529fa5c077cf346a40c078cc832347672fd579f5 100644
--- a/core/modules/contextual/contextual.module
+++ b/core/modules/contextual/contextual.module
@@ -25,7 +25,7 @@ function contextual_menu() {
  */
 function contextual_toolbar() {
 
-  if (!Drupal::currentUser()->hasPermission('access contextual links')) {
+  if (!\Drupal::currentUser()->hasPermission('access contextual links')) {
     return;
   }
 
@@ -64,7 +64,7 @@ function contextual_toolbar() {
  */
 function contextual_page_build(&$page) {
 
-  if (!Drupal::currentUser()->hasPermission('access contextual links')) {
+  if (!\Drupal::currentUser()->hasPermission('access contextual links')) {
     return;
   }
 
@@ -109,7 +109,7 @@ function contextual_library_info() {
   $libraries['drupal.contextual-links'] = array(
     'title' => 'Contextual Links',
     'website' => 'http://drupal.org/node/473268',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       // Add the JavaScript, with a group and weight such that it will run
       // before modules/contextual/js/contextual.toolbar.js.
@@ -131,7 +131,7 @@ function contextual_library_info() {
   );
   $libraries['drupal.contextual-toolbar'] = array(
     'title' => 'Contextual Links Toolbar Tab',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       // Add the JavaScript, with a group and weight such that it will run
       // before modules/overlay/overlay-parent.js.
diff --git a/core/modules/dblog/dblog.module b/core/modules/dblog/dblog.module
index 7c431555bde2151eea410fae4ec75e660f4a6982..d14b6e2b39cf072b7fc458ca54625568b2cc72c4 100644
--- a/core/modules/dblog/dblog.module
+++ b/core/modules/dblog/dblog.module
@@ -97,7 +97,7 @@ function dblog_page_build(&$page) {
  */
 function dblog_cron() {
   // Cleanup the watchdog table.
-  $row_limit = Drupal::config('dblog.settings')->get('row_limit');
+  $row_limit = \Drupal::config('dblog.settings')->get('row_limit');
 
   // For row limit n, get the wid of the nth row in descending wid order.
   // Counting the most recent n rows avoids issues with wid number sequences,
@@ -167,7 +167,7 @@ function dblog_form_system_logging_settings_alter(&$form, $form_state) {
   $form['dblog_row_limit'] = array(
     '#type' => 'select',
     '#title' => t('Database log messages to keep'),
-    '#default_value' => Drupal::config('dblog.settings')->get('row_limit'),
+    '#default_value' => \Drupal::config('dblog.settings')->get('row_limit'),
     '#options' => array(0 => t('All')) + drupal_map_assoc(array(100, 1000, 10000, 100000, 1000000)),
     '#description' => t('The maximum number of messages to keep in the database log. Requires a <a href="@cron">cron maintenance task</a>.', array('@cron' => url('admin/reports/status')))
   );
@@ -181,5 +181,5 @@ function dblog_form_system_logging_settings_alter(&$form, $form_state) {
  * @see dblog_form_system_logging_settings_alter()
  */
 function dblog_logging_settings_submit($form, &$form_state) {
-  Drupal::config('dblog.settings')->set('row_limit', $form_state['values']['dblog_row_limit'])->save();
+  \Drupal::config('dblog.settings')->set('row_limit', $form_state['values']['dblog_row_limit'])->save();
 }
diff --git a/core/modules/edit/edit.module b/core/modules/edit/edit.module
index d23f650393afb9b3cef5f6ec5d30b17ff39b2645..f37cd5c745eb3b2278f26fcea47b5524d0a3a3d4 100644
--- a/core/modules/edit/edit.module
+++ b/core/modules/edit/edit.module
@@ -55,7 +55,7 @@ function edit_permission() {
  * editing' permission.
  */
 function edit_page_build(&$page) {
-  if (!Drupal::currentUser()->hasPermission('access in-place editing')) {
+  if (!\Drupal::currentUser()->hasPermission('access in-place editing')) {
     return;
   }
 
@@ -79,7 +79,7 @@ function edit_library_info() {
   );
   $libraries['edit'] = array(
     'title' => 'Edit: in-place editing',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       // Core.
       $path . '/js/edit.js' => $options,
@@ -121,7 +121,7 @@ function edit_library_info() {
   );
   $libraries['edit.editorWidget.form'] = array(
     'title' => 'Form in-place editor',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/editors/formEditor.js' => $options,
     ),
@@ -131,7 +131,7 @@ function edit_library_info() {
   );
   $libraries['edit.editorWidget.direct'] = array(
     'title' => 'Direct in-place editor',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/editors/directEditor.js' => $options,
     ),
diff --git a/core/modules/editor/editor.module b/core/modules/editor/editor.module
index 00445df5b801a89a4a759c684730e13982d6e269..e843c2d3b0ca8a1264b70ed55dcdb81ffefd504b 100644
--- a/core/modules/editor/editor.module
+++ b/core/modules/editor/editor.module
@@ -71,7 +71,7 @@ function editor_library_info() {
 
   $libraries['drupal.editor.admin'] = array(
     'title' => 'Text Editor',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/editor.admin.js' => array(),
     ),
@@ -82,7 +82,7 @@ function editor_library_info() {
   );
   $libraries['drupal.editor'] = array(
     'title' => 'Text Editor',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/editor.js' => array(),
     ),
@@ -99,7 +99,7 @@ function editor_library_info() {
 
   $libraries['drupal.editor.dialog'] = array(
     'title' => 'Text Editor Dialog',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/editor.dialog.js' => array('weight' => 2),
     ),
@@ -113,7 +113,7 @@ function editor_library_info() {
 
   $libraries['edit.formattedTextEditor.editor'] = array(
     'title' => 'Formatted text editor',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/js/editor.formattedTextEditor.js' => array(
         'scope' => 'footer',
@@ -165,7 +165,7 @@ function editor_form_filter_admin_overview_alter(&$form, $form_state) {
   $form['formats']['#header'] = array_merge($start, $form['formats']['#header']);
 
   // Then splice in the name of each text editor for each text format.
-  $editors = Drupal::service('plugin.manager.editor')->getDefinitions();
+  $editors = \Drupal::service('plugin.manager.editor')->getDefinitions();
   foreach (element_children($form['formats']) as $format_id) {
     $editor = editor_load($format_id);
     $editor_name = ($editor && isset($editors[$editor->editor])) ? $editors[$editor->editor]['label'] : drupal_placeholder('—');
@@ -183,7 +183,7 @@ function editor_form_filter_format_form_alter(&$form, &$form_state) {
   if (!isset($form_state['editor'])) {
     $format_id = $form_state['controller']->getEntity()->id();
     $form_state['editor'] = editor_load($format_id);
-    $form_state['editor_manager'] = Drupal::service('plugin.manager.editor');
+    $form_state['editor_manager'] = \Drupal::service('plugin.manager.editor');
   }
   $editor = $form_state['editor'];
   $manager = $form_state['editor_manager'];
@@ -383,7 +383,7 @@ function editor_pre_render_format($element) {
   $element['#attached']['library'][] = array('editor', 'drupal.editor');
 
   // Attach attachments for all available editors.
-  $manager = Drupal::service('plugin.manager.editor');
+  $manager = \Drupal::service('plugin.manager.editor');
   $element['#attached'] = NestedArray::mergeDeep($element['#attached'], $manager->getAttachments($format_ids));
 
   return $element;
diff --git a/core/modules/editor/tests/modules/editor_test.module b/core/modules/editor/tests/modules/editor_test.module
index cdaf52e12b75ca846fe9faae5afc91df698ecd1d..fc2d748c665e9ca8ec4cad88a4be62700e3d6543 100644
--- a/core/modules/editor/tests/modules/editor_test.module
+++ b/core/modules/editor/tests/modules/editor_test.module
@@ -31,7 +31,7 @@ function editor_test_editor_default_settings_alter(&$settings, $editor) {
  */
 function editor_test_editor_js_settings_alter(&$settings) {
   // Allow tests to enable or disable this alter hook.
-  if (!Drupal::state()->get('editor_test_js_settings_alter_enabled', FALSE)) {
+  if (!\Drupal::state()->get('editor_test_js_settings_alter_enabled', FALSE)) {
     return;
   }
 
diff --git a/core/modules/email/email.module b/core/modules/email/email.module
index 6ee5916cd6cc8a7a0a35a16f9743dc4bf265ac66..5a5f116a8af9f9e63cd89d5b8afee896a020b425 100644
--- a/core/modules/email/email.module
+++ b/core/modules/email/email.module
@@ -31,7 +31,7 @@ function email_help($path, $arg) {
  * Implements hook_field_info_alter().
  */
 function email_field_info_alter(&$info) {
-  if (Drupal::moduleHandler()->moduleExists('text')) {
+  if (\Drupal::moduleHandler()->moduleExists('text')) {
     $info['email']['default_formatter'] = 'text_plain';
   }
 }
diff --git a/core/modules/entity/entity.install b/core/modules/entity/entity.install
index 9cbd71e5c7e8860c0d05f89ebb483c2fcba5f4f2..95d485bd88215e1d8278057dac62d757c8932d80 100644
--- a/core/modules/entity/entity.install
+++ b/core/modules/entity/entity.install
@@ -25,7 +25,7 @@
  */
 function _update_8000_entity_get_display($entity_type, $bundle, $view_mode) {
   $id = $entity_type . '.' . $bundle . '.' . $view_mode;
-  $config = Drupal::config("entity.display.$id");
+  $config = \Drupal::config("entity.display.$id");
   if ($config->get()) {
     return $config;
   }
@@ -64,7 +64,7 @@ function _update_8000_entity_get_display($entity_type, $bundle, $view_mode) {
  */
 function _update_8000_entity_get_form_display($entity_type, $bundle, $form_mode) {
   $id = $entity_type . '.' . $bundle . '.' . $form_mode;
-  $config = Drupal::config("entity.form_display.$id");
+  $config = \Drupal::config("entity.form_display.$id");
   if ($config->get()) {
     return $config;
   }
diff --git a/core/modules/entity_reference/entity_reference.module b/core/modules/entity_reference/entity_reference.module
index 10364d8b27f569fdaed6780902b7097406d4d201..b9e7c58ca0fa2760089a0a7a544843f14c5317aa 100644
--- a/core/modules/entity_reference/entity_reference.module
+++ b/core/modules/entity_reference/entity_reference.module
@@ -15,7 +15,7 @@
  * Implements hook_field_info_alter().
  */
 function entity_reference_field_info_alter(&$info) {
-  if (!Drupal::moduleHandler()->moduleExists('node')) {
+  if (!\Drupal::moduleHandler()->moduleExists('node')) {
     // Fall back to another primary entity type if the Node module is not
     // available.
     $info['entity_reference']['settings']['target_type'] = 'user';
@@ -171,7 +171,7 @@ function entity_reference_settings_ajax_submit($form, &$form_state) {
  * Implements hook_options_list().
  */
 function entity_reference_options_list(FieldDefinitionInterface $field_definition, EntityInterface $entity) {
-  if (!$options = Drupal::service('plugin.manager.entity_reference.selection')->getSelectionHandler($field_definition, $entity)->getReferenceableEntities()) {
+  if (!$options = \Drupal::service('plugin.manager.entity_reference.selection')->getSelectionHandler($field_definition, $entity)->getReferenceableEntities()) {
     return array();
   }
 
diff --git a/core/modules/field/field.deprecated.inc b/core/modules/field/field.deprecated.inc
index 8ac601e3b0d0f5736db53ba1ee1fb638addc1a7a..fad633994949b3578e835208b33f945af2423802 100644
--- a/core/modules/field/field.deprecated.inc
+++ b/core/modules/field/field.deprecated.inc
@@ -24,16 +24,16 @@
  *   keyed by field type name.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::service('plugin.manager.entity.field.field_type')->getDefinition()
+ *   \Drupal::service('plugin.manager.entity.field.field_type')->getDefinition()
  *   or
- *   Drupal::service('plugin.manager.entity.field.field_type')->getDefinitions()
+ *   \Drupal::service('plugin.manager.entity.field.field_type')->getDefinitions()
  */
 function field_info_field_types($field_type = NULL) {
   if ($field_type) {
-    return Drupal::service('plugin.manager.entity.field.field_type')->getDefinition($field_type);
+    return \Drupal::service('plugin.manager.entity.field.field_type')->getDefinition($field_type);
   }
   else {
-    return Drupal::service('plugin.manager.entity.field.field_type')->getDefinitions();
+    return \Drupal::service('plugin.manager.entity.field.field_type')->getDefinitions();
   }
 }
 
@@ -48,7 +48,7 @@ function field_info_field_types($field_type = NULL) {
  *   are not defined.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::service('plugin.manager.entity.field.field_type')->getDefaultSettings()
+ *   \Drupal::service('plugin.manager.entity.field.field_type')->getDefaultSettings()
  */
 function field_info_field_settings($type) {
   return \Drupal::service('plugin.manager.entity.field.field_type')->getDefaultSettings($type);
@@ -65,7 +65,7 @@ function field_info_field_settings($type) {
  *   settings are not defined.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::service('plugin.manager.entity.field.field_type')->getDefaultInstanceSettings()
+ *   \Drupal::service('plugin.manager.entity.field.field_type')->getDefaultInstanceSettings()
  */
 function field_info_instance_settings($type) {
   return \Drupal::service('plugin.manager.entity.field.field_type')->getDefaultInstanceSettings($type);
@@ -83,9 +83,9 @@ function field_info_instance_settings($type) {
  *   or an array of all existing widget types, keyed by widget type name.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::service('plugin.manager.field.widget')->getDefinition()
+ *   \Drupal::service('plugin.manager.field.widget')->getDefinition()
  *   or
- *   Drupal::service('plugin.manager.field.widget')->getDefinitions()
+ *   \Drupal::service('plugin.manager.field.widget')->getDefinitions()
  */
 function field_info_widget_types($widget_type = NULL) {
   if ($widget_type) {
@@ -108,7 +108,7 @@ function field_info_widget_types($widget_type = NULL) {
  *   undefined.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::service('plugin.manager.field.widget')->getDefaultSettings()
+ *   \Drupal::service('plugin.manager.field.widget')->getDefaultSettings()
  */
 function field_info_widget_settings($type) {
   return \Drupal::service('plugin.manager.field.widget')->getDefaultSettings($type);
@@ -127,9 +127,9 @@ function field_info_widget_settings($type) {
  *   formatter type name.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::service('plugin.manager.field.formatter')->getDefinition()
+ *   \Drupal::service('plugin.manager.field.formatter')->getDefinition()
  *   or
- *   Drupal::service('plugin.manager.field.formatter')->getDefinitions()
+ *   \Drupal::service('plugin.manager.field.formatter')->getDefinitions()
  */
 function field_info_formatter_types($formatter_type = NULL) {
   if ($formatter_type) {
@@ -152,7 +152,7 @@ function field_info_formatter_types($formatter_type = NULL) {
  *   undefined.
  *
  * @deprecated as of Drupal 8.0. Use
- *   Drupal::service('plugin.manager.field.formatter')->getDefaultSettings()
+ *   \Drupal::service('plugin.manager.field.formatter')->getDefaultSettings()
  */
 function field_info_formatter_settings($type) {
   return \Drupal::service('plugin.manager.field.formatter')->getDefaultSettings($type);
@@ -577,7 +577,7 @@ function field_attach_form(EntityInterface $entity, &$form, &$form_state, $langc
   // Let other modules make changes to the form.
   // Avoid \Drupal::moduleHandler()->invokeAll()
   // to let parameters be taken by reference.
-  foreach (Drupal::moduleHandler()->getImplementations('field_attach_form') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('field_attach_form') as $module) {
     $function = $module . '_field_attach_form';
     $function($entity, $form, $form_state, $langcode);
   }
@@ -673,7 +673,7 @@ function field_attach_extract_form_values(EntityInterface $entity, $form, &$form
   // Let other modules act on submitting the entity.
   // Avoid \Drupal::moduleHandler()->invokeAll()
   // to let $form_state be taken by reference.
-  foreach (Drupal::moduleHandler()->getImplementations('field_attach_extract_form_values') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('field_attach_extract_form_values') as $module) {
     $function = $module . 'field_attach_extract_form_values';
     $function($entity, $form, $form_state);
   }
diff --git a/core/modules/field/field.info.inc b/core/modules/field/field.info.inc
index 9bb495c99d099644bea8a77b494f93752f55bd57..79345a84efa34af5ca4ac1f165738a15fcd4be00 100644
--- a/core/modules/field/field.info.inc
+++ b/core/modules/field/field.info.inc
@@ -38,8 +38,8 @@ function field_info_cache_clear() {
   entity_info_cache_clear();
 
   // Clear typed data definitions.
-  Drupal::typedData()->clearCachedDefinitions();
-  Drupal::service('plugin.manager.entity.field.field_type')->clearCachedDefinitions();
+  \Drupal::typedData()->clearCachedDefinitions();
+  \Drupal::service('plugin.manager.entity.field.field_type')->clearCachedDefinitions();
 
   Field::fieldInfo()->flush();
 }
diff --git a/core/modules/field/field.install b/core/modules/field/field.install
index feed708040f8f348b021ddf95a62043c568e21d5..cf7dd115752176c1d1c073416ef823c3fb0eaee0 100644
--- a/core/modules/field/field.install
+++ b/core/modules/field/field.install
@@ -43,7 +43,7 @@ function _update_8003_field_create_field(array &$field_config) {
   );
 
   // Save in config.
-  Drupal::config('field.field.' . $field_config['id'])
+  \Drupal::config('field.field.' . $field_config['id'])
     ->setData($field_config)
     ->save();
 
@@ -88,7 +88,7 @@ function _update_8003_field_create_instance(array $field_config, array &$instanc
   );
 
   // Save in config.
-  Drupal::config('field.instance.' . $instance_config['id'])
+  \Drupal::config('field.instance.' . $instance_config['id'])
     ->setData($instance_config)
     ->save();
 }
@@ -116,7 +116,7 @@ function _update_8006_field_write_data_sql($entity_type, $bundle, $entity_id, $r
     $revision_id = $entity_id;
   }
 
-  $field_config = Drupal::config("field.field.$entity_type.$field_name");
+  $field_config = \Drupal::config("field.field.$entity_type.$field_name");
   $field = new Field($field_config);
 
   $table_name = DatabaseStorageController::_fieldTableName($field);
@@ -313,7 +313,7 @@ function field_update_8002() {
 function field_update_8003() {
   $uuid = new Uuid();
 
-  $state = Drupal::state();
+  $state = \Drupal::state();
   $deleted_fields = $state->get('field.field.deleted') ?: array();
   $deleted_instances = $state->get('field.instance.deleted') ?: array();
 
@@ -348,7 +348,7 @@ function field_update_8003() {
 
     // Save in either config or state.
     if (!$record['deleted']) {
-      Drupal::config('field.field.' . $config['id'])
+      \Drupal::config('field.field.' . $config['id'])
         ->setData($config)
         ->save();
     }
@@ -403,7 +403,7 @@ function field_update_8003() {
 
     // Save in either config or state.
     if (!$record['deleted']) {
-      Drupal::config('field.instance.' . $config['id'])
+      \Drupal::config('field.instance.' . $config['id'])
         ->setData($config)
         ->save();
     }
@@ -448,7 +448,7 @@ function field_update_8004() {
 function field_update_8005() {
   $uuid = new Uuid();
 
-  $user_default_form_display = Drupal::config('entity.form_display.user.user.default');
+  $user_default_form_display = \Drupal::config('entity.form_display.user.user.default');
   $user_register_config_data = array(
     'id' => 'user.user.register',
     'uuid' => $uuid->generate(),
@@ -458,7 +458,7 @@ function field_update_8005() {
     'content' => array(),
   );
   foreach (config_get_storage_names_with_prefix('field.instance') as $config_id) {
-    $instance_config = Drupal::config($config_id);
+    $instance_config = \Drupal::config($config_id);
     if ($instance_config->get('entity_type') == 'user' && $instance_config->get('settings.user_register_form')) {
       list(, , $field_id) = explode('.', $instance_config->get('id'));
       $user_register_config_data['content'][$field_id] = $user_default_form_display->get('content.' . $field_id);
@@ -469,7 +469,7 @@ function field_update_8005() {
   }
 
   // Save the new 'register' form display.
-  Drupal::config('entity.form_display.user.user.register')
+  \Drupal::config('entity.form_display.user.user.register')
     ->setData($user_register_config_data)
     ->save();
 }
@@ -481,7 +481,7 @@ function field_update_8005() {
 function field_update_8006(&$sandbox) {
   // Get field definitions from config, and deleted fields from state system.
   $config_names = config_get_storage_names_with_prefix('field.field');
-  $deleted_fields = Drupal::state()->get('field.field.deleted') ?: array();
+  $deleted_fields = \Drupal::state()->get('field.field.deleted') ?: array();
   // Ditch UUID keys, we will iterate through deleted fields using a numeric
   // index.
   $deleted_fields = array_values($deleted_fields);
@@ -498,7 +498,7 @@ function field_update_8006(&$sandbox) {
   // Retrieve the next field definition. When the index exceeds the number of
   // 'configuration' fields, use it to iterate on deleted fields.
   if (isset($config_names[$sandbox['index']])) {
-    $field_config = Drupal::config($config_names[$sandbox['index']])->get();
+    $field_config = \Drupal::config($config_names[$sandbox['index']])->get();
   }
   else {
     $field_config = $deleted_fields[$sandbox['index'] - count($config_names)];
diff --git a/core/modules/field/field.module b/core/modules/field/field.module
index cc7ad90e688a3f104eb6b2890ba9f6135a5b0615..e5ef622e14f38547ea78f5b4f7e07b4f3f706478 100644
--- a/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -125,12 +125,12 @@ function field_help($path, $arg) {
       // order by displayed module name (module names are not translated).
       $items = array();
       $info = system_get_info('module');
-      $modules = array_merge(Drupal::moduleHandler()->getImplementations('field_info'), Drupal::moduleHandler()->getImplementations('field_widget_info'));
+      $modules = array_merge(\Drupal::moduleHandler()->getImplementations('field_info'), \Drupal::moduleHandler()->getImplementations('field_widget_info'));
       $modules = array_unique($modules);
       sort($modules);
       foreach ($modules as $module) {
         $display = $info[$module]['name'];
-        if (Drupal::moduleHandler()->implementsHook($module, 'help')) {
+        if (\Drupal::moduleHandler()->implementsHook($module, 'help')) {
           $items['items'][] = l($display, 'admin/help/' . $module);
         }
         else {
@@ -168,7 +168,7 @@ function field_cron() {
   field_sync_field_status();
 
   // Do a pass of purging on deleted Field API data, if any exists.
-  $limit = Drupal::config('field.settings')->get('purge_batch_size');
+  $limit = \Drupal::config('field.settings')->get('purge_batch_size');
   field_purge_batch($limit);
 }
 
@@ -356,13 +356,13 @@ function field_modules_disabled($modules) {
  * Refreshes the 'active' and 'storage[active]' values for fields.
  */
 function field_sync_field_status() {
-  $module_handler = Drupal::moduleHandler();
-  $state = Drupal::state();
+  $module_handler = \Drupal::moduleHandler();
+  $state = \Drupal::state();
 
   // Get both deleted and non-deleted field definitions.
   $fields = array();
   foreach (config_get_storage_names_with_prefix('field.field.') as $name) {
-    $field = Drupal::config($name)->get();
+    $field = \Drupal::config($name)->get();
     $fields[$field['uuid']] = $field;
   }
   $deleted_fields = $state->get('field.field.deleted') ?: array();
@@ -376,7 +376,7 @@ function field_sync_field_status() {
   // modules.
   $changed = array();
   $modules = $module_handler->getModuleList();
-  $field_types = Drupal::service('plugin.manager.entity.field.field_type')->getDefinitions();
+  $field_types = \Drupal::service('plugin.manager.entity.field.field_type')->getDefinitions();
   // Set fields with missing field type modules to inactive.
   foreach ($fields as $uuid => &$field) {
     // Associate field types.
@@ -397,7 +397,7 @@ function field_sync_field_status() {
       $deleted_fields[$uuid] = $field;
     }
     else {
-      Drupal::config('field.field.' . $field['id'])
+      \Drupal::config('field.field.' . $field['id'])
         ->set('module', $field['module'])
         ->set('active', $field['active'])
         ->save();
@@ -749,7 +749,7 @@ function field_access($op, FieldInterface $field, $entity_type, $entity = NULL,
     $account = $user;
   }
 
-  foreach (Drupal::moduleHandler()->getImplementations('field_access') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('field_access') as $module) {
     $function = $module . '_field_access';
     $access = $function($op, $field, $entity_type, $entity, $account);
     if ($access === FALSE) {
diff --git a/core/modules/field/field.multilingual.inc b/core/modules/field/field.multilingual.inc
index d02595c5bf8e67132d767440f2665f33e73116dd..ce14a254d32f21fde86b491e560f0bc024f05a36 100644
--- a/core/modules/field/field.multilingual.inc
+++ b/core/modules/field/field.multilingual.inc
@@ -198,7 +198,7 @@ function field_content_languages() {
  * Checks whether field language fallback is enabled.
  */
 function field_language_fallback_enabled() {
-  return language_multilingual() && Drupal::config('field.settings')->get('language_fallback');
+  return language_multilingual() && \Drupal::config('field.settings')->get('language_fallback');
 }
 
 /**
diff --git a/core/modules/field/field.purge.inc b/core/modules/field/field.purge.inc
index 5ab55ef23726914022b1d7a6a266ec9611e3fa54..df304678c9d3d7d8dd4248c67017f88cbe261355 100644
--- a/core/modules/field/field.purge.inc
+++ b/core/modules/field/field.purge.inc
@@ -73,7 +73,7 @@ function field_purge_batch($batch_size) {
   // Retrieve all deleted field instances. We cannot use field_info_instances()
   // because that function does not return deleted instances.
   $instances = field_read_instances(array('deleted' => TRUE), array('include_deleted' => TRUE));
-  $factory = Drupal::service('entity.query');
+  $factory = \Drupal::service('entity.query');
   $info = entity_get_info();
   foreach ($instances as $instance) {
     $entity_type = $instance['entity_type'];
@@ -111,7 +111,7 @@ function field_purge_batch($batch_size) {
         $ids->revision_id = $revision_id;
         $ids->entity_id = $entity_id;
         $entity = _field_create_entity_from_ids($ids);
-        Drupal::entityManager()->getStorageController($entity_type)->onFieldItemsPurge($entity, $instance);
+        \Drupal::entityManager()->getStorageController($entity_type)->onFieldItemsPurge($entity, $instance);
       }
     }
     else {
@@ -121,7 +121,7 @@ function field_purge_batch($batch_size) {
   }
 
   // Retrieve all deleted fields. Any that have no instances can be purged.
-  $deleted_fields = Drupal::state()->get('field.field.deleted') ?: array();
+  $deleted_fields = \Drupal::state()->get('field.field.deleted') ?: array();
   foreach ($deleted_fields as $field) {
     $field = new Field($field);
 
@@ -149,7 +149,7 @@ function field_purge_batch($batch_size) {
  *   The instance record to purge.
  */
 function field_purge_instance($instance) {
-  $state = Drupal::state();
+  $state = \Drupal::state();
   $deleted_instances = $state->get('field.instance.deleted');
   unset($deleted_instances[$instance['uuid']]);
   $state->set('field.instance.deleted', $deleted_instances);
@@ -158,7 +158,7 @@ function field_purge_instance($instance) {
   field_info_cache_clear();
 
   // Invoke external hooks after the cache is cleared for API consistency.
-  Drupal::moduleHandler()->invokeAll('field_purge_instance', array($instance));
+  \Drupal::moduleHandler()->invokeAll('field_purge_instance', array($instance));
 }
 
 /**
@@ -176,19 +176,19 @@ function field_purge_field($field) {
     throw new FieldException(t('Attempt to purge a field @field_name that still has instances.', array('@field_name' => $field['field_name'])));
   }
 
-  $state = Drupal::state();
+  $state = \Drupal::state();
   $deleted_fields = $state->get('field.field.deleted');
   unset($deleted_fields[$field['uuid']]);
   $state->set('field.field.deleted', $deleted_fields);
 
   // Notify the storage layer.
-  Drupal::entityManager()->getStorageController($field->entity_type)->onFieldPurge($field);
+  \Drupal::entityManager()->getStorageController($field->entity_type)->onFieldPurge($field);
 
   // Clear the cache.
   field_info_cache_clear();
 
   // Invoke external hooks after the cache is cleared for API consistency.
-  Drupal::moduleHandler()->invokeAll('field_purge_field', array($field));
+  \Drupal::moduleHandler()->invokeAll('field_purge_field', array($field));
 }
 
 /**
diff --git a/core/modules/field/field.views.inc b/core/modules/field/field.views.inc
index d6d9e97559dc4671c98e3d58feea250d3ff4a919..8269575a97d6dcc018246ae0d0e0f7b580bad387 100644
--- a/core/modules/field/field.views.inc
+++ b/core/modules/field/field.views.inc
@@ -20,7 +20,7 @@
  */
 function field_views_data() {
   $data = array();
-  $module_handler = Drupal::moduleHandler();
+  $module_handler = \Drupal::moduleHandler();
 
   foreach (field_info_fields() as $field) {
     if (_field_views_is_sql_entity_type($field)) {
@@ -68,7 +68,7 @@ function field_views_data_alter(&$data) {
  *   True if the entity type uses DatabaseStorageController.
  */
 function _field_views_is_sql_entity_type(FieldInterface $field) {
-  $entity_manager = Drupal::entityManager();
+  $entity_manager = \Drupal::entityManager();
   try {
     if ($entity_manager->getStorageController($field->entity_type) instanceof DatabaseStorageController) {
       return TRUE;
@@ -129,7 +129,7 @@ function field_views_field_default_views_data(FieldInterface $field) {
   $field_name = $field['field_name'];
 
   // Grab information about the entity type tables.
-  $entity_manager = Drupal::entityManager();
+  $entity_manager = \Drupal::entityManager();
   $entity_type = $field->entity_type;
   $entity_info = $entity_manager->getDefinition($entity_type);
   if (!isset($entity_info['base_table'])) {
diff --git a/core/modules/field/lib/Drupal/field/Plugin/Type/FieldType/LegacyFieldTypeDiscoveryDecorator.php b/core/modules/field/lib/Drupal/field/Plugin/Type/FieldType/LegacyFieldTypeDiscoveryDecorator.php
index 2936b47093b74f6a53e2fbc8a268b5d3d78e58e6..2fc45a4396b8d2c1024596269e47bfd8c165e37d 100644
--- a/core/modules/field/lib/Drupal/field/Plugin/Type/FieldType/LegacyFieldTypeDiscoveryDecorator.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Type/FieldType/LegacyFieldTypeDiscoveryDecorator.php
@@ -57,7 +57,7 @@ public function getDefinitions() {
     $definitions = $this->decorated->getDefinitions();
 
     // We cannot use HookDiscovery, since it uses
-    // Drupal::moduleHandler()->getImplementations(), which
+    // \Drupal::moduleHandler()->getImplementations(), which
     // throws exceptions during upgrades.
     foreach (array_keys($this->moduleHandler->getModuleList()) as $module) {
       $function = $module . '_field_info';
diff --git a/core/modules/field/tests/modules/field_test/field_test.entity.inc b/core/modules/field/tests/modules/field_test/field_test.entity.inc
index 8f140e3a4b2580606854dfc66a66bdcc78915e8e..3d4b0fabdb16fe65f635b45f4e5f7a9c0fb27d85 100644
--- a/core/modules/field/tests/modules/field_test/field_test.entity.inc
+++ b/core/modules/field/tests/modules/field_test/field_test.entity.inc
@@ -14,7 +14,7 @@
 function field_test_entity_info() {
   // If requested, clear the field cache while this is being called. See
   // Drupal\field\Tests\FieldInfoTest::testFieldInfoCache().
-  if (Drupal::state()->get('field_test.clear_info_cache_in_hook_entity_info')) {
+  if (\Drupal::state()->get('field_test.clear_info_cache_in_hook_entity_info')) {
     field_info_cache_clear();
   }
 }
diff --git a/core/modules/field/tests/modules/field_test/field_test.module b/core/modules/field/tests/modules/field_test/field_test.module
index 3ab0c7ee29e575d3f7f04a09e56b1d4ad92e26ba..42c019fceb48c980037a99a720e5073435e94e74 100644
--- a/core/modules/field/tests/modules/field_test/field_test.module
+++ b/core/modules/field/tests/modules/field_test/field_test.module
@@ -56,7 +56,7 @@ function field_test_menu() {
  * Implements hook_field_available_languages_alter().
  */
 function field_test_field_available_languages_alter(&$langcodes, $context) {
-  if (Drupal::state()->get('field_test.field_available_languages_alter')) {
+  if (\Drupal::state()->get('field_test.field_available_languages_alter')) {
     // Add an unavailable language code.
     $langcodes[] = 'xx';
     // Remove an available language code.
@@ -69,7 +69,7 @@ function field_test_field_available_languages_alter(&$langcodes, $context) {
  * Implements hook_field_language_alter().
  */
 function field_test_field_language_alter(&$display_langcode, $context) {
-  if (Drupal::state()->get('field_test.language_fallback') ?: TRUE) {
+  if (\Drupal::state()->get('field_test.language_fallback') ?: TRUE) {
     field_language_fallback($display_langcode, $context['entity'], $context['langcode']);
   }
 }
diff --git a/core/modules/field_ui/field_ui.module b/core/modules/field_ui/field_ui.module
index 9d49073e324bd7eb91145f8879e31e68d9aa7433..0d81232edf6029f92af5241fb849969851b35ee0 100644
--- a/core/modules/field_ui/field_ui.module
+++ b/core/modules/field_ui/field_ui.module
@@ -264,7 +264,7 @@ function field_ui_entity_info(&$entity_info) {
 function field_ui_entity_bundle_create($entity_type, $bundle) {
   // When a new bundle is created, the menu needs to be rebuilt to add our
   // menu item tabs.
-  Drupal::state()->set('menu_rebuild_needed', TRUE);
+  \Drupal::state()->set('menu_rebuild_needed', TRUE);
 }
 
 /**
@@ -273,7 +273,7 @@ function field_ui_entity_bundle_create($entity_type, $bundle) {
 function field_ui_entity_bundle_rename($entity_type, $bundle_old, $bundle_new) {
   // When a bundle is renamed, the menu needs to be rebuilt to add our
   // menu item tabs.
-  Drupal::state()->set('menu_rebuild_needed', TRUE);
+  \Drupal::state()->set('menu_rebuild_needed', TRUE);
 }
 
 /**
@@ -338,7 +338,7 @@ function field_ui_entity_operation_alter(array &$operations, EntityInterface $en
  */
 function field_ui_form_node_type_form_submit($form, &$form_state) {
   if ($form_state['triggering_element']['#parents'][0] === 'save_continue') {
-    $admin_path = Drupal::entityManager()->getAdminPath('node', $form_state['values']['type']);
+    $admin_path = \Drupal::entityManager()->getAdminPath('node', $form_state['values']['type']);
     $form_state['redirect'] = "$admin_path/fields";
   }
 }
@@ -349,7 +349,7 @@ function field_ui_form_node_type_form_submit($form, &$form_state) {
 function field_ui_library_info() {
   $libraries['drupal.field_ui'] = array(
     'title' => 'Field UI',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'field_ui') . '/field_ui.js' => array(),
     ),
@@ -371,14 +371,14 @@ function field_ui_library_info() {
  * Implements hook_view_mode_presave().
  */
 function field_ui_view_mode_presave(EntityViewModeInterface $view_mode) {
-  Drupal::state()->set('menu_rebuild_needed', TRUE);
+  \Drupal::state()->set('menu_rebuild_needed', TRUE);
 }
 
 /**
  * Implements hook_view_mode_delete().
  */
 function field_ui_view_mode_delete(EntityViewModeInterface $view_mode) {
-  Drupal::state()->set('menu_rebuild_needed', TRUE);
+  \Drupal::state()->set('menu_rebuild_needed', TRUE);
 }
 
 /**
diff --git a/core/modules/file/file.field.inc b/core/modules/file/file.field.inc
index d3a583bbd1bb12b912e0d9bfd4aa316f15be8106..430f79f2b7bc8bbd2ad1f8aeff3f4a05a74e3352 100644
--- a/core/modules/file/file.field.inc
+++ b/core/modules/file/file.field.inc
@@ -116,7 +116,7 @@ function file_field_widget_process($element, &$form_state, $form) {
 
   // Add the description field if enabled.
   if ($element['#description_field'] && $item['fids']) {
-    $config = Drupal::config('file.settings');
+    $config = \Drupal::config('file.settings');
     $element['description'] = array(
       '#type' => $config->get('description.type'),
       '#title' => t('Description'),
diff --git a/core/modules/file/file.install b/core/modules/file/file.install
index 33717c2291d274131947119bbb3d0e23c1fcdb6d..7fb57720a0a6271775f61300b4bd86e111f82852 100644
--- a/core/modules/file/file.install
+++ b/core/modules/file/file.install
@@ -163,7 +163,7 @@ function file_requirements($phase) {
   // Check the server's ability to indicate upload progress.
   if ($phase == 'runtime') {
     $implementation = file_progress_implementation();
-    $server_software = Drupal::request()->server->get('SERVER_SOFTWARE');
+    $server_software = \Drupal::request()->server->get('SERVER_SOFTWARE');
     $apache = strpos($server_software, 'Apache') !== FALSE;
     $fastcgi = strpos($server_software, 'mod_fastcgi') !== FALSE || strpos($server_software, 'mod_fcgi') !== FALSE;
     $description = NULL;
@@ -266,7 +266,7 @@ function file_update_8002() {
  */
 function file_update_8003() {
   foreach (config_get_storage_names_with_prefix('field.field.') as $config_name) {
-    $field_config = Drupal::config($config_name);
+    $field_config = \Drupal::config($config_name);
     // Only update file fields that use the default SQL storage.
     if (in_array($field_config->get('type'), array('file', 'image'))) {
       $field = new Field($field_config->get());
diff --git a/core/modules/file/file.module b/core/modules/file/file.module
index 3316ece42d8788014e67336e8e5b81fef333f947..68b33cfa49d263178ca13f7aa8ee37a354ac8e8d 100644
--- a/core/modules/file/file.module
+++ b/core/modules/file/file.module
@@ -123,7 +123,7 @@ function file_load($fid, $reset = FALSE) {
  * @return Drupal\file\FileUsage\FileUsageInterface.
  */
 function file_usage() {
-  return Drupal::service('file.usage');
+  return \Drupal::service('file.usage');
 }
 
 /**
@@ -195,7 +195,7 @@ function file_copy(File $source, $destination = NULL, $replace = FILE_EXISTS_REN
     $file->save();
 
     // Inform modules that the file has been copied.
-    Drupal::moduleHandler()->invokeAll('file_copy', array($file, $source));
+    \Drupal::moduleHandler()->invokeAll('file_copy', array($file, $source));
 
     return $file;
   }
@@ -270,7 +270,7 @@ function file_move(File $source, $destination = NULL, $replace = FILE_EXISTS_REN
     $file->save();
 
     // Inform modules that the file has been moved.
-    Drupal::moduleHandler()->invokeAll('file_move', array($file, $source));
+    \Drupal::moduleHandler()->invokeAll('file_move', array($file, $source));
 
     // Delete the original if it's not in use elsewhere.
     if ($delete_source && !file_usage()->listUsage($source)) {
@@ -314,7 +314,7 @@ function file_validate(File $file, $validators = array()) {
   }
 
   // Let other modules perform validation on the new file.
-  return array_merge($errors, Drupal::moduleHandler()->invokeAll('file_validate', array($file)));
+  return array_merge($errors, \Drupal::moduleHandler()->invokeAll('file_validate', array($file)));
 }
 
 /**
@@ -381,7 +381,7 @@ function file_validate_extensions(File $file, $extensions) {
  * @see hook_file_validate()
  */
 function file_validate_size(File $file, $file_limit = 0, $user_limit = 0) {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
   $errors = array();
 
   if ($file_limit && $file->getSize() > $file_limit) {
@@ -389,7 +389,7 @@ function file_validate_size(File $file, $file_limit = 0, $user_limit = 0) {
   }
 
   // Save a query by only calling spaceUsed() when a limit is provided.
-  if ($user_limit && (Drupal::entityManager()->getStorageController('file')->spaceUsed($user->id()) + $file->getSize()) > $user_limit) {
+  if ($user_limit && (\Drupal::entityManager()->getStorageController('file')->spaceUsed($user->id()) + $file->getSize()) > $user_limit) {
     $errors[] = t('The file is %filesize which would exceed your disk quota of %quota.', array('%filesize' => format_size($file->getSize()), '%quota' => format_size($user_limit)));
   }
 
@@ -410,7 +410,7 @@ function file_validate_size(File $file, $file_limit = 0, $user_limit = 0) {
 function file_validate_is_image(File $file) {
   $errors = array();
 
-  $image = Drupal::service('image.factory')->get($file->getFileUri());
+  $image = \Drupal::service('image.factory')->get($file->getFileUri());
   if (!$image->getExtension()) {
     $errors[] = t('Only JPEG, PNG and GIF images are allowed.');
   }
@@ -445,7 +445,7 @@ function file_validate_image_resolution(File $file, $maximum_dimensions = 0, $mi
   $errors = array();
 
   // Check first that the file is an image.
-  $image_factory = Drupal::service('image.factory');
+  $image_factory = \Drupal::service('image.factory');
   $image = $image_factory->get($file->getFileUri());
   if ($image->getExtension()) {
     if ($maximum_dimensions) {
@@ -502,7 +502,7 @@ function file_validate_image_resolution(File $file, $maximum_dimensions = 0, $mi
  * @see file_unmanaged_save_data()
  */
 function file_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
 
   if (empty($destination)) {
     $destination = file_default_scheme() . '://';
@@ -600,7 +600,7 @@ function file_theme() {
  * be re-used by other File-like modules, such as Image.
  */
 function file_file_download($uri, $field_type = 'file') {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
 
   // Get the file record based on the URI. If not in the database just return.
   $files = entity_load_multiple_by_properties('file', array('uri' => $uri));
@@ -651,7 +651,7 @@ function file_file_download($uri, $field_type = 'file') {
         // Invoke hook and collect grants/denies for download access.
         // Default to FALSE and let entities overrule this ruling.
         $grants = array('system' => FALSE);
-        foreach (Drupal::moduleHandler()->getImplementations('file_download_access') as $module) {
+        foreach (\Drupal::moduleHandler()->getImplementations('file_download_access') as $module) {
           $grants = array_merge($grants, array($module => module_invoke($module, 'file_download_access', $field, $entity, $file)));
         }
         // Allow other modules to alter the returned grants/denies.
@@ -693,7 +693,7 @@ function file_file_download($uri, $field_type = 'file') {
  * Implements file_cron()
  */
 function file_cron() {
-  $result = Drupal::entityManager()->getStorageController('file')->retrieveTemporaryFiles();
+  $result = \Drupal::entityManager()->getStorageController('file')->retrieveTemporaryFiles();
   foreach ($result as $row) {
     if ($file = file_load($row->fid)) {
       $references = file_usage()->listUsage($file);
@@ -758,7 +758,7 @@ function file_cron() {
  *   - destination: Path to the file after it is moved (same as 'uri').
  */
 function file_save_upload($form_field_name, $validators = array(), $destination = FALSE, $delta = NULL, $replace = FILE_EXISTS_RENAME) {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
   static $upload_cache;
 
   // Make sure there's an upload to process.
@@ -857,7 +857,7 @@ function file_save_upload($form_field_name, $validators = array(), $destination
     // rename filename.php.foo and filename.php to filename.php.foo.txt and
     // filename.php.txt, respectively). Don't rename if 'allow_insecure_uploads'
     // evaluates to TRUE.
-    if (!Drupal::config('system.file')->get('allow_insecure_uploads') && preg_match('/\.(php|pl|py|cgi|asp|js)(\.|$)/i', $file->getFilename()) && (substr($file->getFilename(), -4) != '.txt')) {
+    if (!\Drupal::config('system.file')->get('allow_insecure_uploads') && preg_match('/\.(php|pl|py|cgi|asp|js)(\.|$)/i', $file->getFilename()) && (substr($file->getFilename(), -4) != '.txt')) {
       $file->setMimeType('text/plain');
       $file->setFileUri($file->getFileUri() . '.txt');
       $file->setFilename($file->getFilename() . '.txt');
@@ -989,7 +989,7 @@ function file_file_predelete(File $file) {
  * Implements hook_tokens().
  */
 function file_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $url_options = array('absolute' => TRUE);
   if (isset($options['langcode'])) {
@@ -1646,7 +1646,7 @@ function file_icon_url(File $file, $icon_directory = NULL) {
 function file_icon_path(File $file, $icon_directory = NULL) {
   // Use the default set of icons if none specified.
   if (!isset($icon_directory)) {
-    $icon_directory = Drupal::config('file.settings')->get('icon.directory');
+    $icon_directory = \Drupal::config('file.settings')->get('icon.directory');
   }
 
   // If there's an icon matching the exact mimetype, go for it.
@@ -1922,7 +1922,7 @@ function file_get_file_references(File $file, $field = NULL, $age = EntityStorag
 function file_library_info() {
   $libraries['drupal.file'] = array(
     'title' => 'File',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'file') . '/file.js' => array(),
     ),
diff --git a/core/modules/file/tests/file_test/file_test.module b/core/modules/file/tests/file_test/file_test.module
index 90fc9006ff6f2948ff083e2aaa668ac6abbf3a44..e5a10a04a41b36b402a27f529299b3bfe7d9b84a 100644
--- a/core/modules/file/tests/file_test/file_test.module
+++ b/core/modules/file/tests/file_test/file_test.module
@@ -54,14 +54,14 @@ function file_test_reset() {
     'move' => array(),
     'delete' => array(),
   );
-  Drupal::state()->set('file_test.results', $results);
+  \Drupal::state()->set('file_test.results', $results);
 
   // These hooks will return these values, see file_test_set_return().
   $return = array(
     'validate' => array(),
     'download' => NULL,
   );
-  Drupal::state()->set('file_test.return', $return);
+  \Drupal::state()->set('file_test.return', $return);
 }
 
 /**
@@ -79,7 +79,7 @@ function file_test_reset() {
  * @see file_test_reset()
  */
 function file_test_get_calls($op) {
-  $results = Drupal::state()->get('file_test.results') ?: array();
+  $results = \Drupal::state()->get('file_test.results') ?: array();
   return $results[$op];
 }
 
@@ -92,7 +92,7 @@ function file_test_get_calls($op) {
  *   passed to each call.
  */
 function file_test_get_all_calls() {
-  return Drupal::state()->get('file_test.results') ?: array();
+  return \Drupal::state()->get('file_test.results') ?: array();
 }
 
 /**
@@ -108,9 +108,9 @@ function file_test_get_all_calls() {
  * @see file_test_reset()
  */
 function _file_test_log_call($op, $args) {
-  $results = Drupal::state()->get('file_test.results') ?: array();
+  $results = \Drupal::state()->get('file_test.results') ?: array();
   $results[$op][] = $args;
-  Drupal::state()->set('file_test.results', $results);
+  \Drupal::state()->set('file_test.results', $results);
 }
 
 /**
@@ -126,7 +126,7 @@ function _file_test_log_call($op, $args) {
  * @see file_test_reset()
  */
 function _file_test_get_return($op) {
-  $return = Drupal::state()->get('file_test.return') ?: array($op => NULL);
+  $return = \Drupal::state()->get('file_test.return') ?: array($op => NULL);
   return $return[$op];
 }
 
@@ -142,9 +142,9 @@ function _file_test_get_return($op) {
  * @see file_test_reset()
  */
 function file_test_set_return($op, $value) {
-  $return = Drupal::state()->get('file_test.return') ?: array();
+  $return = \Drupal::state()->get('file_test.return') ?: array();
   $return[$op] = $value;
-  Drupal::state()->set('file_test.return', $return);
+  \Drupal::state()->set('file_test.return', $return);
 }
 
 /**
@@ -216,7 +216,7 @@ function file_test_file_predelete(File $file) {
 function file_test_file_url_alter(&$uri) {
   // Only run this hook when this variable is set. Otherwise, we'd have to add
   // another hidden test module just for this hook.
-  $alter_mode = Drupal::state()->get('file_test.hook_file_url_alter');
+  $alter_mode = \Drupal::state()->get('file_test.hook_file_url_alter');
   if (!$alter_mode) {
     return;
   }
diff --git a/core/modules/filter/filter.install b/core/modules/filter/filter.install
index 718daee85480a745d090acc88421c8f222712aa0..0390d7944d2c339e08f1a66e48347ad3f606ae85 100644
--- a/core/modules/filter/filter.install
+++ b/core/modules/filter/filter.install
@@ -49,7 +49,7 @@ function filter_update_8001() {
     $format['filters'] = $filters;
 
     // Save the config object.
-    $config = Drupal::config('filter.format.' . $id);
+    $config = \Drupal::config('filter.format.' . $id);
     $config->setData($format);
     $config->save();
   }
diff --git a/core/modules/filter/filter.module b/core/modules/filter/filter.module
index 4c9990940a08a45dec5fb988ce93c87dac5e5d20..2cdc2752e516ceaa253a631aabc8615c1329ab5f 100644
--- a/core/modules/filter/filter.module
+++ b/core/modules/filter/filter.module
@@ -201,14 +201,14 @@ function filter_formats(AccountInterface $account = NULL) {
 
   // All available formats are cached for performance.
   if (!isset($formats['all'])) {
-    $language_interface = Drupal::languageManager()->getLanguage(Language::TYPE_INTERFACE);
-    if ($cache = Drupal::cache()->get("filter_formats:{$language_interface->id}")) {
+    $language_interface = \Drupal::languageManager()->getLanguage(Language::TYPE_INTERFACE);
+    if ($cache = \Drupal::cache()->get("filter_formats:{$language_interface->id}")) {
       $formats['all'] = $cache->data;
     }
     else {
-      $formats['all'] = Drupal::entityManager()->getStorageController('filter_format')->loadByProperties(array('status' => '1'));
+      $formats['all'] = \Drupal::entityManager()->getStorageController('filter_format')->loadByProperties(array('status' => '1'));
       uasort($formats['all'], 'Drupal\Core\Config\Entity\ConfigEntityBase::sort');
-      Drupal::cache()->set("filter_formats:{$language_interface->id}", $formats['all'], CacheBackendInterface::CACHE_PERMANENT, array('filter_formats' => TRUE));
+      \Drupal::cache()->set("filter_formats:{$language_interface->id}", $formats['all'], CacheBackendInterface::CACHE_PERMANENT, array('filter_formats' => TRUE));
     }
   }
 
@@ -528,7 +528,7 @@ function filter_fallback_format() {
   // existing (and potentially unsafe) text format on the site automatically
   // available to all users. Returning NULL at least guarantees that this
   // cannot happen.
-  return Drupal::config('filter.settings')->get('fallback_format');
+  return \Drupal::config('filter.settings')->get('fallback_format');
 }
 
 /**
@@ -737,7 +737,7 @@ function filter_process_format($element) {
   // If multiple text formats are available, remove the fallback. The
   // "always_show_fallback_choice" is a hidden variable that has no UI. It
   // defaults to false.
-  if (!Drupal::config('filter.settings')->get('always_show_fallback_choice')) {
+  if (!\Drupal::config('filter.settings')->get('always_show_fallback_choice')) {
     $fallback_format = filter_fallback_format();
     if ($element['#format'] !== $fallback_format && count($formats) > 1) {
       unset($formats[$fallback_format]);
@@ -1079,7 +1079,7 @@ function _filter_url($text, $filter) {
   // we cannot cleanly differ between protocols here without hard-coding MAILTO,
   // so '//' is optional for all protocols.
   // @see filter_xss_bad_protocol()
-  $protocols = Drupal::config('system.filter')->get('protocols');
+  $protocols = \Drupal::config('system.filter')->get('protocols');
   $protocols = implode(':(?://)?|', $protocols) . ':(?://)?';
 
   $valid_url_path_characters = "[\p{L}\p{M}\p{N}!\*\';:=\+,\.\$\/%#\[\]\-_~@&]";
@@ -1384,7 +1384,7 @@ function _filter_html_image_secure_process($text) {
     $src = $image->getAttribute('src');
     // Remove absolute URLs pointing to the local domain to prevent mixed
     // content errors.
-    $request = Drupal::request();
+    $request = \Drupal::request();
     $image->setAttribute('src', preg_replace('|^https?://' . $request->getHost() . '|', '', $src));
 
     // Verify that $src starts with $base_path.
@@ -1456,7 +1456,7 @@ function filter_library_info() {
 
   $libraries['drupal.filter.admin'] = array(
     'title' => 'Filter',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/filter.admin.js' => array(),
     ),
@@ -1472,7 +1472,7 @@ function filter_library_info() {
   );
   $libraries['drupal.filter.filter_html.admin'] = array(
     'title' => 'Automatic "Limit allowed HTML tags" filter setting updating.',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/filter.filter_html.admin.js' => array(),
     ),
@@ -1484,7 +1484,7 @@ function filter_library_info() {
   );
   $libraries['drupal.filter'] = array(
     'title' => 'Filter',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/filter.js' => array(),
     ),
@@ -1499,7 +1499,7 @@ function filter_library_info() {
   );
   $libraries['caption'] = array(
     'title' => 'Captions for images and alignments',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'css' => array(
       $path . '/css/filter.caption.css',
     ),
diff --git a/core/modules/forum/forum.install b/core/modules/forum/forum.install
index e4b1e26352e0cacd9d5eb1a2fb5aad99e2490ebf..1b06ad7b11cc5894e5bdf105b79ca4335b5550c2 100644
--- a/core/modules/forum/forum.install
+++ b/core/modules/forum/forum.install
@@ -14,9 +14,9 @@ function forum_install() {
   // Set the weight of the forum.module to 1 so it is loaded after the taxonomy.module.
   module_set_weight('forum', 1);
   // Do not allow to delete the forum's node type machine name.
-  $locked = Drupal::state()->get('node.type.locked');
+  $locked = \Drupal::state()->get('node.type.locked');
   $locked['forum'] = 'forum';
-  Drupal::state()->set('node.type.locked', $locked);
+  \Drupal::state()->set('node.type.locked', $locked);
 }
 
 /**
@@ -26,7 +26,7 @@ function forum_enable() {
   // Create the forum vocabulary if it does not exist.
   // @todo Change Forum module so forum.settings can contain the vocabulary's
   //   machine name.
-  $config = Drupal::config('forum.settings');
+  $config = \Drupal::config('forum.settings');
   // If the module was disabled only, the current config may contain a valid
   // vocabulary ID already.
   $vocabulary = entity_load('taxonomy_vocabulary', $config->get('vocabulary'));
@@ -115,7 +115,7 @@ function forum_enable() {
  * Implements hook_modules_preinstall().
  */
 function forum_modules_preinstall($modules) {
-  $list_boolean = Drupal::service('plugin.manager.entity.field.field_type')->getDefinition('list_boolean');
+  $list_boolean = \Drupal::service('plugin.manager.entity.field.field_type')->getDefinition('list_boolean');
   if (empty($list_boolean) && in_array('forum', $modules)) {
     // Make sure that the list_boolean field type is available before our
     // default config is installed.
@@ -145,9 +145,9 @@ function forum_uninstall() {
   field_purge_batch(10);
   field_purge_batch(10);
   // Allow to delete a forum's node type.
-  $locked = Drupal::state()->get('node.type.locked');
+  $locked = \Drupal::state()->get('node.type.locked');
   unset($locked['forum']);
-  Drupal::state()->set('node.type.locked', $locked);
+  \Drupal::state()->set('node.type.locked', $locked);
 }
 
 /**
diff --git a/core/modules/forum/forum.module b/core/modules/forum/forum.module
index 0a1739b84fa26729c45deb52dcecd6f970af445f..0fe30f683cf4cf6e501d6a092c374cb856380d6e 100644
--- a/core/modules/forum/forum.module
+++ b/core/modules/forum/forum.module
@@ -151,9 +151,9 @@ function forum_menu_local_tasks(&$data, $router_item, $root_path) {
 
   // Add action link to 'node/add/forum' on 'forum' sub-pages.
   if ($root_path == 'forum' || $root_path == 'forum/%') {
-    $request = Drupal::request();
+    $request = \Drupal::request();
     $forum_term = $request->attributes->get('taxonomy_term');
-    $vid = Drupal::config('forum.settings')->get('vocabulary');
+    $vid = \Drupal::config('forum.settings')->get('vocabulary');
     $links = array();
     // Loop through all bundles for forum taxonomy vocabulary field.
     $field = Field::fieldInfo()->getField('node', 'taxonomy_forums');
@@ -215,7 +215,7 @@ function forum_entity_info(&$info) {
  */
 function forum_entity_bundle_info_alter(&$bundles) {
   // Take over URI construction for taxonomy terms that are forums.
-  if ($vid = Drupal::config('forum.settings')->get('vocabulary')) {
+  if ($vid = \Drupal::config('forum.settings')->get('vocabulary')) {
     if (isset($bundles['taxonomy_term'][$vid])) {
       $bundles['taxonomy_term'][$vid]['uri_callback'] = 'forum_uri';
     }
@@ -238,7 +238,7 @@ function forum_uri($forum) {
  * forum taxonomy.
  */
 function forum_node_validate(EntityInterface $node, $form) {
-  if (Drupal::service('forum_manager')->checkNodeType($node)) {
+  if (\Drupal::service('forum_manager')->checkNodeType($node)) {
     // vocabulary is selected, not a "container" term.
     if (!$node->taxonomy_forums->isEmpty()) {
       // Extract the node's proper topic ID.
@@ -272,7 +272,7 @@ function forum_node_validate(EntityInterface $node, $form) {
  * Assigns the forum taxonomy when adding a topic from within a forum.
  */
 function forum_node_presave(EntityInterface $node) {
-  if (Drupal::service('forum_manager')->checkNodeType($node)) {
+  if (\Drupal::service('forum_manager')->checkNodeType($node)) {
     // Make sure all fields are set properly:
     $node->icon = !empty($node->icon) ? $node->icon : '';
     if (!$node->taxonomy_forums->isEmpty()) {
@@ -293,7 +293,7 @@ function forum_node_presave(EntityInterface $node) {
  * Implements hook_node_update().
  */
 function forum_node_update(EntityInterface $node) {
-  if (Drupal::service('forum_manager')->checkNodeType($node)) {
+  if (\Drupal::service('forum_manager')->checkNodeType($node)) {
     // If this is not a new revision and does exist, update the forum record,
     // otherwise insert a new one.
     if ($node->getRevisionId() == $node->original->getRevisionId() && db_query('SELECT tid FROM {forum} WHERE nid=:nid', array(':nid' => $node->id()))->fetchField()) {
@@ -358,7 +358,7 @@ function forum_node_update(EntityInterface $node) {
       $query->execute();
       // The logic for determining last_comment_count is fairly complex, so
       // update the index too.
-      Drupal::service('forum_manager')->updateIndex($node->id());
+      \Drupal::service('forum_manager')->updateIndex($node->id());
     }
     // When a forum node is unpublished, remove it from the forum_index table.
     else {
@@ -371,7 +371,7 @@ function forum_node_update(EntityInterface $node) {
  * Implements hook_node_insert().
  */
 function forum_node_insert(EntityInterface $node) {
-  if (Drupal::service('forum_manager')->checkNodeType($node)) {
+  if (\Drupal::service('forum_manager')->checkNodeType($node)) {
     if (!empty($node->forum_tid)) {
       $nid = db_insert('forum')
         ->fields(array(
@@ -406,7 +406,7 @@ function forum_node_insert(EntityInterface $node) {
  * Implements hook_node_predelete().
  */
 function forum_node_predelete(EntityInterface $node) {
-  if (Drupal::service('forum_manager')->checkNodeType($node)) {
+  if (\Drupal::service('forum_manager')->checkNodeType($node)) {
     db_delete('forum')
       ->condition('nid', $node->id())
       ->execute();
@@ -422,7 +422,7 @@ function forum_node_predelete(EntityInterface $node) {
 function forum_node_load($nodes) {
   $node_vids = array();
   foreach ($nodes as $node) {
-    if (Drupal::service('forum_manager')->checkNodeType($node)) {
+    if (\Drupal::service('forum_manager')->checkNodeType($node)) {
       $node_vids[] = $node->getRevisionId();
     }
   }
@@ -457,7 +457,7 @@ function forum_permission() {
  * $comment->save() calls hook_comment_publish() for all published comments.
  */
 function forum_comment_publish($comment) {
-  Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
+  \Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
 }
 
 /**
@@ -470,7 +470,7 @@ function forum_comment_update($comment) {
   // $comment->save() calls hook_comment_publish() for all published comments,
   // so we need to handle all other values here.
   if (!$comment->status->value) {
-    Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
+    \Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
   }
 }
 
@@ -478,21 +478,21 @@ function forum_comment_update($comment) {
  * Implements hook_comment_unpublish().
  */
 function forum_comment_unpublish($comment) {
-  Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
+  \Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
 }
 
 /**
  * Implements hook_comment_delete().
  */
 function forum_comment_delete($comment) {
-  Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
+  \Drupal::service('forum_manager')->updateIndex($comment->nid->target_id);
 }
 
 /**
  * Implements hook_form_BASE_FORM_ID_alter().
  */
 function forum_form_taxonomy_vocabulary_form_alter(&$form, &$form_state, $form_id) {
-  $vid = Drupal::config('forum.settings')->get('vocabulary');
+  $vid = \Drupal::config('forum.settings')->get('vocabulary');
   $vocabulary = $form_state['controller']->getEntity();
   if ($vid == $vocabulary->id()) {
     $form['help_forum_vocab'] = array(
@@ -514,7 +514,7 @@ function forum_form_taxonomy_vocabulary_form_alter(&$form, &$form_state, $form_i
  * Implements hook_form_FORM_ID_alter() for taxonomy_term_form().
  */
 function forum_form_taxonomy_term_form_alter(&$form, &$form_state, $form_id) {
-  $vid = Drupal::config('forum.settings')->get('vocabulary');
+  $vid = \Drupal::config('forum.settings')->get('vocabulary');
   if (isset($form['vid']['#value']) && $form['vid']['#value'] == $vid) {
     // Hide multiple parents select from forum terms.
     $form['relations']['parent']['#access'] = FALSE;
@@ -683,7 +683,7 @@ function template_preprocess_forum_list(&$variables) {
     $variables['forums'][$id]->icon_class = 'default';
     $variables['forums'][$id]->icon_title = t('No new posts');
     if ($user->isAuthenticated()) {
-      $variables['forums'][$id]->new_topics = Drupal::service('forum_manager')->unreadTopics($forum->id(), $user->id());
+      $variables['forums'][$id]->new_topics = \Drupal::service('forum_manager')->unreadTopics($forum->id(), $user->id());
       if ($variables['forums'][$id]->new_topics) {
         $variables['forums'][$id]->new_text = format_plural($variables['forums'][$id]->new_topics, '1 new post<span class="visually-hidden"> in forum %title</span>', '@count new posts<span class="visually-hidden"> in forum %title</span>', array('%title' => $variables['forums'][$id]->label()));
         $variables['forums'][$id]->new_url = url('forum/' . $forum->id(), array('fragment' => 'new'));
@@ -806,7 +806,7 @@ function template_preprocess_forum_topic_list(&$variables) {
  *   - first_new: Indicates whether this is the first topic with new posts.
  */
 function template_preprocess_forum_icon(&$variables) {
-  $variables['hot_threshold'] = Drupal::config('forum.settings')->get('topics.hot_threshold');
+  $variables['hot_threshold'] = \Drupal::config('forum.settings')->get('topics.hot_threshold');
 
   if ($variables['num_posts'] > $variables['hot_threshold']) {
     $icon_status_class = $variables['new_posts'] ? 'hot-new' : 'hot';
diff --git a/core/modules/history/history.module b/core/modules/history/history.module
index 5b4bd6f7e7768f10f9b5677bd1aec01af7cee739..0b529e0084fc987829620a3ed881d33f6bb07153 100644
--- a/core/modules/history/history.module
+++ b/core/modules/history/history.module
@@ -113,7 +113,7 @@ function history_user_delete($account) {
 function history_library_info() {
   $libraries['drupal.history'] = array(
     'title' => 'History',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'history') . '/js/history.js' => array(),
     ),
diff --git a/core/modules/image/image.admin.inc b/core/modules/image/image.admin.inc
index f90a4c81aada5de282ab91f739037b1f2a7050bb..b8f9c9642d004bd24d84c5c48bd7258beb42f04e 100644
--- a/core/modules/image/image.admin.inc
+++ b/core/modules/image/image.admin.inc
@@ -75,13 +75,13 @@ function theme_image_style_effects($variables) {
 function theme_image_style_preview($variables) {
   $style = $variables['style'];
 
-  $sample_image = Drupal::config('image.settings')->get('preview_image');
+  $sample_image = \Drupal::config('image.settings')->get('preview_image');
   $sample_width = 160;
   $sample_height = 160;
 
   // Set up original file information.
   $original_path = $sample_image;
-  $image_factory = Drupal::service('image.factory');
+  $image_factory = \Drupal::service('image.factory');
   $original_image = $image_factory->get($original_path);
   $original_image = array(
     'width' => $original_image->getWidth(),
diff --git a/core/modules/image/image.field.inc b/core/modules/image/image.field.inc
index 4b1118d7e7a417bac64a6d3fd85e63660cc7811d..1111b8a221b254bebd7f5a27c737779c22ec80f4 100644
--- a/core/modules/image/image.field.inc
+++ b/core/modules/image/image.field.inc
@@ -40,7 +40,7 @@ function image_field_widget_process($element, &$form_state, $form) {
       $variables['height'] = $element['#value']['height'];
     }
     else {
-      $image = Drupal::service('image.factory')->get($file->getFileUri());
+      $image = \Drupal::service('image.factory')->get($file->getFileUri());
       if ($image->getExtension()) {
         $variables['width'] = $image->getWidth();
         $variables['height'] = $image->getHeight();
diff --git a/core/modules/image/image.install b/core/modules/image/image.install
index bbeb77735b14ad7a7caa6a7977f8dd686ab5988d..ae80170622cb8c072c8371f16a5cc3bcb4cf2824 100644
--- a/core/modules/image/image.install
+++ b/core/modules/image/image.install
@@ -111,7 +111,7 @@ function image_update_8000() {
 
   // Convert each style into a configuration object.
   foreach ($styles as $name => $style) {
-    $config = Drupal::config('image.style.' . $name);
+    $config = \Drupal::config('image.style.' . $name);
     $config->set('name', $name);
     $config->set('effects', $style['effects']);
     $config->save();
diff --git a/core/modules/image/image.module b/core/modules/image/image.module
index ee59456fee996f1f61394dbd439c8d1c5ac3492b..e3d14978307e0dae8a563292aa587af3c343d6fd 100644
--- a/core/modules/image/image.module
+++ b/core/modules/image/image.module
@@ -69,7 +69,7 @@ function image_help($path, $arg) {
     case 'admin/config/media/image-styles':
       return '<p>' . t('Image styles commonly provide thumbnail sizes by scaling and cropping images, but can also add various effects before an image is displayed. When an image is displayed with a style, a new file is created and the original image is left unchanged.') . '</p>';
     case 'admin/config/media/image-styles/manage/%/add/%':
-      $effect = Drupal::service('plugin.manager.image.effect')->getDefinition($arg[7]);
+      $effect = \Drupal::service('plugin.manager.image.effect')->getDefinition($arg[7]);
       return isset($effect['description']) ? ('<p>' . $effect['description'] . '</p>') : NULL;
     case 'admin/config/media/image-styles/manage/%/effects/%':
       $effect = entity_load('image_style', $arg[5])->getEffect($arg[7])->getPluginDefinition();
@@ -248,10 +248,10 @@ function image_file_download($uri) {
     $original_uri = file_uri_scheme($uri) . '://' . implode('/', $args);
 
     // Check that the file exists and is an image.
-    $image = Drupal::service('image.factory')->get($uri);
+    $image = \Drupal::service('image.factory')->get($uri);
     if ($image->getExtension()) {
       // Check the permissions of the original to grant access to this image.
-      $headers = Drupal::moduleHandler()->invokeAll('file_download', array($original_uri));
+      $headers = \Drupal::moduleHandler()->invokeAll('file_download', array($original_uri));
       // Confirm there's at least one module granting access and none denying access.
       if (!empty($headers) && !in_array(-1, $headers)) {
         return array(
diff --git a/core/modules/image/tests/modules/image_module_test/image_module_test.module b/core/modules/image/tests/modules/image_module_test/image_module_test.module
index 7d64d2c86fa0c1d544b5084bb8a261406c2cca72..0242f1e7ff6ca9e8f72dc8cd9836fe15109bff11 100644
--- a/core/modules/image/tests/modules/image_module_test/image_module_test.module
+++ b/core/modules/image/tests/modules/image_module_test/image_module_test.module
@@ -6,7 +6,7 @@
  */
 
 function image_module_test_file_download($uri) {
-  $default_uri = Drupal::state()->get('image.test_file_download') ?: FALSE;
+  $default_uri = \Drupal::state()->get('image.test_file_download') ?: FALSE;
   if ($default_uri == $uri) {
     return array('X-Image-Owned-By' => 'image_module_test');
   }
diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index 3ebaab124ed352a2f46d86ed6a0e7c9da6acadc0..562580b3b29766d13d6e171d1445416502791f41 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -37,7 +37,7 @@ function language_negotiation_configure_form() {
     '#language_negotiation_info' => language_negotiation_info(),
   );
   $form['#language_types'] = array();
-  $configurable = Drupal::config('system.language.types')->get('configurable');
+  $configurable = \Drupal::config('system.language.types')->get('configurable');
   foreach ($form['#language_types_info'] as $type => $info) {
     // Show locked language types only if they are configurable.
     if (empty($info['locked']) || in_array($type, $configurable)) {
@@ -73,7 +73,7 @@ function language_negotiation_configure_form_table(&$form, $type) {
   );
   // Only show configurability checkbox for the unlocked language types.
   if (empty($info['locked'])) {
-    $configurable = Drupal::config('system.language.types')->get('configurable');
+    $configurable = \Drupal::config('system.language.types')->get('configurable');
     $table_form['configurable'] = array(
       '#type' => 'checkbox',
       '#title' => t('Customize %language_name language detection to differ from User interface text language detection settings.', array('%language_name' => $info['name'])),
@@ -236,7 +236,7 @@ function theme_language_negotiation_configure_form($variables) {
 function language_negotiation_configure_form_submit($form, &$form_state) {
   $configurable_types = $form['#language_types'];
 
-  $stored_values = Drupal::config('system.language.types')->get('configurable');
+  $stored_values = \Drupal::config('system.language.types')->get('configurable');
   $customized = array();
   $method_weights_type = array();
 
@@ -276,7 +276,7 @@ function language_negotiation_configure_form_submit($form, &$form_state) {
     // made not configurable, deactivate it first.
     $non_configurable = array_keys(array_diff($customized, array_filter($customized)));
     _language_disable_language_switcher($non_configurable);
-    Drupal::service('plugin.manager.block')->clearCachedDefinitions();
+    \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
   }
 
   $form_state['redirect'] = 'admin/config/regional/language/detection';
diff --git a/core/modules/language/language.install b/core/modules/language/language.install
index 42f9c37639f9da3995172a47dcab30b9fe1fda40..1753bfdb46991fe7d542696a4bedd7a63ec9baec 100644
--- a/core/modules/language/language.install
+++ b/core/modules/language/language.install
@@ -29,7 +29,7 @@ function language_install() {
 function language_uninstall() {
   // Clear variables.
   variable_del('language_default');
-  Drupal::state()->delete('language_count');
+  \Drupal::state()->delete('language_count');
 
   // Clear variables.
   variable_del('language_types');
@@ -62,7 +62,7 @@ function language_disable() {
   // Force the language_count state to be 1, so that the when checking if the
   // site is multilingual (for example in language_multilingual()), the result
   // will be FALSE, because the language module is disabled.
-  Drupal::state()->set('language_count', 1);
+  \Drupal::state()->set('language_count', 1);
 }
 
 /**
diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index 216211b1c79b78522e496ff6c8e18a7a9994ee6d..6031e338bf217d3f403b580345e8bda164d2d899 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -340,7 +340,7 @@ function language_configuration_element_submit(&$form, &$form_state) {
  *   - language_show: if the language element should be hidden or not.
  */
 function language_save_default_configuration($entity_type, $bundle, $values = array()) {
-  Drupal::config('language.settings')->set(language_get_default_configuration_settings_key($entity_type, $bundle), array('langcode' => $values['langcode'], 'language_show' => $values['language_show']))->save();
+  \Drupal::config('language.settings')->set(language_get_default_configuration_settings_key($entity_type, $bundle), array('langcode' => $values['langcode'], 'language_show' => $values['language_show']))->save();
 }
 
 /**
@@ -357,7 +357,7 @@ function language_save_default_configuration($entity_type, $bundle, $values = ar
  *   - language_show: if the language element is hidden or not.
  */
 function language_get_default_configuration($entity_type, $bundle) {
-  $configuration = Drupal::config('language.settings')->get(language_get_default_configuration_settings_key($entity_type, $bundle));
+  $configuration = \Drupal::config('language.settings')->get(language_get_default_configuration_settings_key($entity_type, $bundle));
   if (is_null($configuration)) {
     $configuration = array();
   }
@@ -374,7 +374,7 @@ function language_get_default_configuration($entity_type, $bundle) {
  *   A string representing the bundle.
  */
 function language_clear_default_configuration($entity_type, $bundle) {
-  Drupal::config('language.settings')->clear(language_get_default_configuration_settings_key($entity_type, $bundle))->save();
+  \Drupal::config('language.settings')->clear(language_get_default_configuration_settings_key($entity_type, $bundle))->save();
 }
 
 /**
@@ -474,7 +474,7 @@ function language_save($language) {
   $language->is_new = $language_entity->isNew();
 
   // Let other modules modify $language before saved.
-  Drupal::moduleHandler()->invokeAll('language_presave', array($language));
+  \Drupal::moduleHandler()->invokeAll('language_presave', array($language));
 
   // Assign language properties to language entity.
   $language_entity->label = isset($language->name) ? $language->name : '';
@@ -486,11 +486,11 @@ function language_save($language) {
   $language_entity->save();
   $t_args = array('%language' => $language->name, '%langcode' => $language->id);
   if ($language->is_new) {
-    Drupal::moduleHandler()->invokeAll('language_insert', array($language));
+    \Drupal::moduleHandler()->invokeAll('language_insert', array($language));
     watchdog('language', 'The %language (%langcode) language has been created.', $t_args);
   }
   else {
-    Drupal::moduleHandler()->invokeAll('language_update', array($language));
+    \Drupal::moduleHandler()->invokeAll('language_update', array($language));
     watchdog('language', 'The %language (%langcode) language has been updated.', $t_args);
   }
 
@@ -531,7 +531,7 @@ function language_update_count() {
       $count++;
     }
   }
-  Drupal::state()->set('language_count', $count);
+  \Drupal::state()->set('language_count', $count);
 }
 
 /**
@@ -548,7 +548,7 @@ function language_delete($langcode) {
   if (isset($languages[$langcode]) && !$languages[$langcode]->locked) {
     $language = $languages[$langcode];
 
-    Drupal::moduleHandler()->invokeAll('language_delete', array($language));
+    \Drupal::moduleHandler()->invokeAll('language_delete', array($language));
 
     // Remove the language.
     entity_delete_multiple('language_entity', array($language->id));
@@ -573,7 +573,7 @@ function language_delete($langcode) {
 function language_library_info() {
   $libraries['language.admin'] = array(
     'title' => 'Language detection admin',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'language') . '/language.admin.js' => array(),
     ),
@@ -780,7 +780,7 @@ function language_preprocess_block(&$variables) {
  *   Drupal language codes as values.
  */
 function language_get_browser_drupal_langcode_mappings() {
-  $config = Drupal::config('language.mappings');
+  $config = \Drupal::config('language.mappings');
   if ($config->isNew()) {
     return array();
   }
@@ -795,7 +795,7 @@ function language_get_browser_drupal_langcode_mappings() {
  *   Drupal language codes as values.
  */
 function language_set_browser_drupal_langcode_mappings($mappings) {
-  $config = Drupal::config('language.mappings');
+  $config = \Drupal::config('language.mappings');
   $config->setData($mappings);
   $config->save();
 }
@@ -817,7 +817,7 @@ function language_update_locked_weights() {
   foreach (language_list(Language::STATE_LOCKED) as $language) {
     $max_weight++;
     // Update system languages weight.
-    Drupal::config('language.entity.' . $language->id)
+    \Drupal::config('language.entity.' . $language->id)
       ->set('weight', $max_weight)
       ->save();
   }
diff --git a/core/modules/language/language.negotiation.inc b/core/modules/language/language.negotiation.inc
index dc69597f44a5691acd649210e52a6c1a60f9a6a9..43cd6075fa4fd5b7bb8b879461843c078abf6ee4 100644
--- a/core/modules/language/language.negotiation.inc
+++ b/core/modules/language/language.negotiation.inc
@@ -249,7 +249,7 @@ function language_from_user_admin(array $languages, Request $request = NULL) {
  *   A valid language code on success, FALSE otherwise.
  */
 function language_from_session($languages) {
-  $param = Drupal::config('language.negotiation')->get('session.parameter');
+  $param = \Drupal::config('language.negotiation')->get('session.parameter');
 
   // Request parameter: we need to update the session parameter only if we have
   // an authenticated user.
@@ -289,7 +289,7 @@ function language_from_url($languages, Request $request = NULL) {
     return $language_url;
   }
 
-  switch (Drupal::config('language.negotiation')->get('url.source')) {
+  switch (\Drupal::config('language.negotiation')->get('url.source')) {
     case LANGUAGE_NEGOTIATION_URL_PREFIX:
 
       $request_path = urldecode(trim($request->getPathInfo(), '/'));
@@ -365,7 +365,7 @@ function language_from_url($languages, Request $request = NULL) {
  */
 function language_url_fallback($language = NULL, $request = NULL, $language_type = Language::TYPE_INTERFACE) {
   $default = language_default();
-  $prefix = (Drupal::config('language.negotiation')->get('url.source') == LANGUAGE_NEGOTIATION_URL_PREFIX);
+  $prefix = (\Drupal::config('language.negotiation')->get('url.source') == LANGUAGE_NEGOTIATION_URL_PREFIX);
 
   // If the default language is not configured to convey language information,
   // a missing URL language information indicates that URL language should be
@@ -406,7 +406,7 @@ function language_switcher_url($type, $path) {
  * Return the session language switcher block.
  */
 function language_switcher_session($type, $path) {
-  $param = Drupal::config('language.negotiation')->get('session.parameter');
+  $param = \Drupal::config('language.negotiation')->get('session.parameter');
   $language_query = isset($_SESSION[$param]) ? $_SESSION[$param] : language($type)->id;
 
   $languages = language_list();
@@ -437,7 +437,7 @@ function language_switcher_session($type, $path) {
  * Reads language prefixes and uses the langcode if no prefix is set.
  */
 function language_negotiation_url_prefixes() {
-  return Drupal::config('language.negotiation')->get('url.prefixes');
+  return \Drupal::config('language.negotiation')->get('url.prefixes');
 }
 
 /**
@@ -462,7 +462,7 @@ function language_negotiation_url_prefixes_update() {
  * Saves language prefix settings.
  */
 function language_negotiation_url_prefixes_save(array $prefixes) {
-  Drupal::config('language.negotiation')
+  \Drupal::config('language.negotiation')
     ->set('url.prefixes', $prefixes)
     ->save();
 }
@@ -471,14 +471,14 @@ function language_negotiation_url_prefixes_save(array $prefixes) {
  * Reads language domains.
  */
 function language_negotiation_url_domains() {
-  return Drupal::config('language.negotiation')->get('url.domains');
+  return \Drupal::config('language.negotiation')->get('url.domains');
 }
 
 /**
  * Saves the language domain settings.
  */
 function language_negotiation_url_domains_save(array $domains) {
-  Drupal::config('language.negotiation')
+  \Drupal::config('language.negotiation')
     ->set('url.domains', $domains)
     ->save();
 }
@@ -495,7 +495,7 @@ function language_url_rewrite_session(&$path, &$options) {
     global $user;
     if (!$user->id()) {
       $languages = language_list();
-      $query_param = check_plain(Drupal::config('language.negotiation')->get('session.parameter'));
+      $query_param = check_plain(\Drupal::config('language.negotiation')->get('session.parameter'));
       $query_value = isset($_GET[$query_param]) ? check_plain($_GET[$query_param]) : NULL;
       $query_rewrite = isset($languages[$query_value]) && language_negotiation_method_enabled(LANGUAGE_NEGOTIATION_SESSION);
     }
diff --git a/core/modules/language/tests/language_test/language_test.module b/core/modules/language/tests/language_test/language_test.module
index c3386cf7b4816555bbd6a6154640b98816491857..33c2b36b5766e59a29f1099c1f1f74581412daf8 100644
--- a/core/modules/language/tests/language_test/language_test.module
+++ b/core/modules/language/tests/language_test/language_test.module
@@ -24,7 +24,7 @@ function language_test_page_build() {
  * Implements hook_language_types_info().
  */
 function language_test_language_types_info() {
-  if (Drupal::state()->get('language_test.language_types')) {
+  if (\Drupal::state()->get('language_test.language_types')) {
     return array(
       'test_language_type' => array(
         'name' => t('Test'),
@@ -42,15 +42,15 @@ function language_test_language_types_info() {
  * Implements hook_language_types_info_alter().
  */
 function language_test_language_types_info_alter(array &$language_types) {
-  if (Drupal::state()->get('language_test.content_language_type')) {
+  if (\Drupal::state()->get('language_test.content_language_type')) {
     $language_types[Language::TYPE_CONTENT]['locked'] = FALSE;
     unset($language_types[Language::TYPE_CONTENT]['fixed']);
     // By default languages are not configurable. Make Language::TYPE_CONTENT
     // configurable.
-    $configurable = Drupal::config('system.language.types')->get('configurable');
+    $configurable = \Drupal::config('system.language.types')->get('configurable');
     if (!in_array(Language::TYPE_CONTENT, $configurable)) {
       $configurable[] = Language::TYPE_CONTENT;
-      Drupal::config('system.language.types')->set('configurable', $configurable)->save();
+      \Drupal::config('system.language.types')->set('configurable', $configurable)->save();
     }
   }
 }
@@ -59,7 +59,7 @@ function language_test_language_types_info_alter(array &$language_types) {
  * Implements hook_language_negotiation_info().
  */
 function language_test_language_negotiation_info() {
-  if (Drupal::state()->get('language_test.language_negotiation_info')) {
+  if (\Drupal::state()->get('language_test.language_negotiation_info')) {
     $info = array(
       'callbacks' => array(
         'negotiation' => 'language_test_language_negotiation_method',
@@ -86,7 +86,7 @@ function language_test_language_negotiation_info() {
  * Implements hook_language_negotiation_info_alter().
  */
 function language_test_language_negotiation_info_alter(array &$negotiation_info) {
-  if (Drupal::state()->get('language_test.language_negotiation_info_alter')) {
+  if (\Drupal::state()->get('language_test.language_negotiation_info_alter')) {
     unset($negotiation_info[LANGUAGE_NEGOTIATION_INTERFACE]);
   }
 }
@@ -100,7 +100,7 @@ function language_test_store_language_negotiation() {
   foreach (language_types_get_all() as $type) {
     $last[$type] = language($type)->id;
   }
-  Drupal::state()->set('language_test.language_negotiation_last', $last);
+  \Drupal::state()->set('language_test.language_negotiation_last', $last);
 }
 
 /**
diff --git a/core/modules/locale/locale.batch.inc b/core/modules/locale/locale.batch.inc
index 008cb50f526a20245d9bbf6321af47a3ddb74f45..d789ea27b86ce875388161b23ea678b2c2338faf 100644
--- a/core/modules/locale/locale.batch.inc
+++ b/core/modules/locale/locale.batch.inc
@@ -94,7 +94,7 @@ function locale_translation_batch_status_check($project, $langcode, $options = a
 function locale_translation_batch_status_finished($success, $results) {
   if ($success) {
     if (isset($results['failed_files'])) {
-        if (Drupal::moduleHandler()->moduleExists('dblog')) {
+        if (\Drupal::moduleHandler()->moduleExists('dblog')) {
           $message = format_plural(count($results['failed_files']), 'One translation file could not be checked. <a href="@url">See the log</a> for details.', '@count translation files could not be checked. <a href="@url">See the log</a> for details.', array('@url' => url('admin/reports/dblog')));
         }
         else {
@@ -112,7 +112,7 @@ function locale_translation_batch_status_finished($success, $results) {
     if (!isset($results['failed_files']) && !isset($results['files'])) {
       drupal_set_message(t('Nothing to check.'));
     }
-    Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
+    \Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
   }
   else {
     drupal_set_message(t('An error occurred trying to check available interface translation updates.'), 'error');
@@ -210,7 +210,7 @@ function locale_translation_batch_fetch_import($project, $langcode, $options, &$
 function locale_translation_batch_fetch_finished($success, $results) {
   module_load_include('bulk.inc', 'locale');
   if ($success) {
-    Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
+    \Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
   }
   return locale_translate_batch_finished($success, $results);
 }
@@ -231,7 +231,7 @@ function locale_translation_batch_fetch_finished($success, $results) {
 function locale_translation_http_check($uri) {
 
   try {
-    $response = Drupal::httpClient()
+    $response = \Drupal::httpClient()
       ->head($uri)
       ->send();
     $result = array();
diff --git a/core/modules/locale/locale.bulk.inc b/core/modules/locale/locale.bulk.inc
index 55c3aedb570e27df40dddc96b66a363b06391272..355ccb198962f9f176d3b50f1a83452c9ffe29cb 100644
--- a/core/modules/locale/locale.bulk.inc
+++ b/core/modules/locale/locale.bulk.inc
@@ -243,7 +243,7 @@ function locale_translate_export_form_submit($form, &$form_state) {
   if (!empty($item)) {
     $uri = tempnam('temporary://', 'po_');
     $header = $reader->getHeader();
-    $header->setProjectName(Drupal::config('system.site')->get('name'));
+    $header->setProjectName(\Drupal::config('system.site')->get('name'));
     $header->setLanguageName($languageName);
 
     $writer = new PoStreamWriter;
@@ -258,7 +258,7 @@ function locale_translate_export_form_submit($form, &$form_state) {
     $response = new BinaryFileResponse($uri);
     $response->setContentDisposition('attachment', $filename);
     // @todo remove lines below once converted to new routing system.
-    $response->prepare(Drupal::request())
+    $response->prepare(\Drupal::request())
       ->send();
   }
   else {
@@ -348,7 +348,7 @@ function locale_translate_get_interface_translation_files($projects = array(), $
   // containing a project name and language code: {project}.{langcode}.po or
   // {project}-{version}.{langcode}.po.
   // Only files of known projects and languages will be returned.
-  $directory = Drupal::config('locale.settings')->get('translation.path');
+  $directory = \Drupal::config('locale.settings')->get('translation.path');
   $result = file_scan_directory($directory, '![a-z_]+(\-[0-9a-z\.\-\+]+|)\.[^\./]+\.po$!', array('recurse' => FALSE));
 
   foreach ($result as $file) {
@@ -602,7 +602,7 @@ function locale_translate_batch_finished($success, $results) {
   if ($success) {
     $additions = $updates = $deletes = $skips = $config = 0;
     if (isset($results['failed_files'])) {
-      if (Drupal::moduleHandler()->moduleExists('dblog')) {
+      if (\Drupal::moduleHandler()->moduleExists('dblog')) {
         $message = format_plural(count($results['failed_files']), 'One translation file could not be imported. <a href="@url">See the log</a> for details.', '@count translation files could not be imported. <a href="@url">See the log</a> for details.', array('@url' => url('admin/reports/dblog')));
       }
       else {
@@ -633,7 +633,7 @@ function locale_translate_batch_finished($success, $results) {
       watchdog('locale', 'Translations imported: %number added, %update updated, %delete removed.', array('%number' => $additions, '%update' => $updates, '%delete' => $deletes));
 
       if ($skips) {
-        if (Drupal::moduleHandler()->moduleExists('dblog')) {
+        if (\Drupal::moduleHandler()->moduleExists('dblog')) {
           $message = format_plural($skips, 'One translation string was skipped because of disallowed or malformed HTML. <a href="@url">See the log</a> for details.', '@count translation strings were skipped because of disallowed or malformed HTML. <a href="@url">See the log</a> for details.', array('@url' => url('admin/reports/dblog')));
         }
         else {
@@ -799,7 +799,7 @@ function locale_config_batch_build(array $names, array $langcodes, $options = ar
     $batch_names[] = $name;
     $i++;
     // During installation the caching of configuration objects is disabled
-    // so it is very expensive to initialize the Drupal::config() object on each request.
+    // so it is very expensive to initialize the \Drupal::config() object on each request.
     // We batch a small number of configuration object upgrades together to
     // improve the overall performance of the process.
     if ($i % 20 == 0) {
diff --git a/core/modules/locale/locale.compare.inc b/core/modules/locale/locale.compare.inc
index db2918fe8e9c1843ca6717b45d49ad310e19f38b..27607605711c3d7400b5db1f8c2b128527355a07 100644
--- a/core/modules/locale/locale.compare.inc
+++ b/core/modules/locale/locale.compare.inc
@@ -20,7 +20,7 @@
  */
 function locale_translation_flush_projects() {
   // Followup issue: http://drupal.org/node/1842362
-  // Replace {locale_project} table by Drupal::state() variable(s).
+  // Replace {locale_project} table by \Drupal::state() variable(s).
   db_truncate('locale_project')->execute();
 }
 
@@ -47,7 +47,7 @@ function locale_translation_flush_projects() {
  */
 function locale_translation_build_projects() {
   // This function depends on Update module. We degrade gracefully.
-  if (!Drupal::moduleHandler()->moduleExists('update')) {
+  if (!\Drupal::moduleHandler()->moduleExists('update')) {
     return array();
   }
 
@@ -92,7 +92,7 @@ function locale_translation_build_projects() {
     // For every project store information.
     $data += array(
       'version' => isset($data['info']['version']) ? $data['info']['version'] : '',
-      'core' => isset($data['info']['core']) ? $data['info']['core'] : Drupal::CORE_COMPATIBILITY,
+      'core' => isset($data['info']['core']) ? $data['info']['core'] : \Drupal::CORE_COMPATIBILITY,
       // A project can provide the path and filename pattern to download the
       // gettext file. Use the default if not.
       'server_pattern' => isset($data['info']['interface translation server pattern']) && $data['info']['interface translation server pattern'] ? $data['info']['interface translation server pattern'] : $default_server['pattern'],
@@ -130,7 +130,7 @@ function locale_translation_project_list() {
   $projects = &drupal_static(__FUNCTION__, array());
   if (empty($projects)) {
     module_load_include('compare.inc', 'update');
-    $config = Drupal::config('locale.settings');
+    $config = \Drupal::config('locale.settings');
     $projects = array();
 
     $additional_whitelist = array(
@@ -195,9 +195,9 @@ function _locale_translation_prepare_project_list($data, $type) {
  *   - "server_pattern": URI containing po file pattern.
  */
 function locale_translation_default_translation_server() {
-  $pattern = Drupal::config('locale.settings')->get('translation.default_server_pattern');
+  $pattern = \Drupal::config('locale.settings')->get('translation.default_server_pattern');
   // An additional check is required here. During the upgrade process
-  // Drupal::config()->get() returns NULL. We use the defined value as fallback.
+  // \Drupal::config()->get() returns NULL. We use the defined value as fallback.
   $pattern  = $pattern ? $pattern : LOCALE_TRANSLATION_DEFAULT_SERVER_PATTERN;
 
   return array(
@@ -226,7 +226,7 @@ function locale_translation_check_projects($projects = array(), $langcodes = arr
   else {
     // Retrieve and save the status of local translations only.
     locale_translation_check_projects_local($projects, $langcodes);
-    Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
+    \Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
   }
 }
 
diff --git a/core/modules/locale/locale.install b/core/modules/locale/locale.install
index 1e62cd40be31f8a6eb0dbbac688a0ab8526f1f2d..d10791c91c68178839cc852c22fd617bf560ab5b 100644
--- a/core/modules/locale/locale.install
+++ b/core/modules/locale/locale.install
@@ -12,9 +12,9 @@
  */
 function locale_install() {
   // Create the interface translations directory and ensure it's writable.
-  if (!$directory = Drupal::config('locale.settings')->get('translation.path')) {
+  if (!$directory = \Drupal::config('locale.settings')->get('translation.path')) {
     $directory = conf_path() . '/files/translations';
-    Drupal::config('locale.settings')->set('translation.path', $directory)->save();
+    \Drupal::config('locale.settings')->set('translation.path', $directory)->save();
   }
   file_prepare_directory($directory, FILE_CREATE_DIRECTORY | FILE_MODIFY_PERMISSIONS);
 }
@@ -23,12 +23,12 @@ function locale_install() {
  * Implements hook_uninstall().
  */
 function locale_uninstall() {
-  $config = Drupal::config('locale.settings');
+  $config = \Drupal::config('locale.settings');
   // Delete all JavaScript translation files.
   $locale_js_directory = 'public://' . $config->get('javascript.directory');
 
   if (is_dir($locale_js_directory)) {
-    $locale_javascripts = Drupal::state()->get('locale.translation.javascript') ?: array();
+    $locale_javascripts = \Drupal::state()->get('locale.translation.javascript') ?: array();
     foreach ($locale_javascripts as $langcode => $file_suffix) {
       if (!empty($file_suffix)) {
         file_unmanaged_delete($locale_js_directory . '/' . $langcode . '_' . $file_suffix . '.js');
@@ -41,9 +41,9 @@ function locale_uninstall() {
   }
 
   // Clear variables.
-  Drupal::state()->delete('system.javascript_parsed');
-  Drupal::state()->delete('locale.translation.plurals');
-  Drupal::state()->delete('locale.translation.javascript');
+  \Drupal::state()->delete('system.javascript_parsed');
+  \Drupal::state()->delete('locale.translation.plurals');
+  \Drupal::state()->delete('locale.translation.javascript');
 
   // Remove all node type language variables. Node module might have been
   // enabled, but may be disabled, so use a wildcard delete.
@@ -468,7 +468,7 @@ function locale_update_8002() {
  */
 function locale_update_8003() {
   $message = '';
-  $config = Drupal::config('language.negotiation');
+  $config = \Drupal::config('language.negotiation');
 
   $domains = $config->get('url.domains') ?: array();
   // $used_domains keeps track of the domain names in use.
@@ -953,7 +953,7 @@ function locale_update_8016() {
   foreach ($result as $format) {
     $language = $format->language;
     // Create config objects for the language if not yet done.
-    Drupal::config("locale.config.$language.system.date_format." . $format->type)
+    \Drupal::config("locale.config.$language.system.date_format." . $format->type)
       ->set('pattern.php', $format->format)
       ->save();
   }
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index d8b4f4096b3918e4a3aaed8eb566672723e53c41..f4266706ae10a0ac656147cc5f21254c40d3b734 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -292,7 +292,7 @@ function locale_language_update($language) {
  */
 function locale_language_delete($language) {
   // Remove translations.
-  Drupal::service('locale.storage')->deleteTranslations(array('language' => $language->id));
+  \Drupal::service('locale.storage')->deleteTranslations(array('language' => $language->id));
 
   // Remove interface translation files.
   module_load_include('inc', 'locale', 'locale.bulk');
@@ -354,7 +354,7 @@ function locale_get_plural($count, $langcode = NULL) {
   if (!isset($plural_indexes[$langcode][$count])) {
     // Retrieve and statically cache the plural formulas for all languages.
     if (empty($plural_formulas)) {
-      $plural_formulas = Drupal::state()->get('locale.translation.plurals') ?: array();
+      $plural_formulas = \Drupal::state()->get('locale.translation.plurals') ?: array();
     }
     // If there is a plural formula for the language, evaluate it for the given
     // $count and statically cache the result for the combination of language
@@ -424,7 +424,7 @@ function locale_cron() {
   // and a translatable language was set.
   // Update tasks are added to the queue here but processed by Drupal's cron
   // using the cron worker defined in locale_queue_info().
-  if ($frequency = Drupal::config('locale.settings')->get('translation.update_interval_days') && locale_translatable_language_list()) {
+  if ($frequency = \Drupal::config('locale.settings')->get('translation.update_interval_days') && locale_translatable_language_list()) {
     module_load_include('translation.inc', 'locale');
     locale_cron_fill_queue();
   }
@@ -494,7 +494,7 @@ function locale_translation_worker($data) {
   // continue the task. This is typically the translation import task.
   if ($batch_context['finished'] < 1) {
     unset($batch_context['strings']);
-    $queue = Drupal::queue('locale_translation', TRUE);
+    $queue = \Drupal::queue('locale_translation', TRUE);
     $queue->createItem(array($function, $args));
   }
 }
@@ -516,7 +516,7 @@ function locale_system_update(array $components) {
   // Skip running the translation imports if in the installer,
   // because it would break out of the installer flow. We have
   // built-in support for translation imports in the installer.
-  if (!drupal_installation_attempted() && locale_translatable_language_list() && Drupal::config('locale.settings')->get('translation.import_enabled')) {
+  if (!drupal_installation_attempted() && locale_translatable_language_list() && \Drupal::config('locale.settings')->get('translation.import_enabled')) {
     module_load_include('compare.inc', 'locale');
 
     // Update the list of translatable projects and start the import batch.
@@ -530,7 +530,7 @@ function locale_system_update(array $components) {
       $batch = locale_translation_batch_update_build($list, array(), $options);
       batch_set($batch);
     }
-    Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
+    \Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
     if ($batch = locale_config_batch_update_components(array(), array(), $components)) {
       batch_set($batch);
     }
@@ -553,7 +553,7 @@ function locale_system_remove($components) {
   $list = array_merge($components['module'], $components['theme']);
   if ($language_list = locale_translatable_language_list()) {
     module_load_include('compare.inc', 'locale');
-    Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
+    \Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
     // Delete configuration translations.
     \Drupal\locale\Locale::config()->deleteComponentTranslations($components, array_keys($language_list));
 
@@ -612,8 +612,8 @@ function locale_js_alter(&$javascript) {
 function locale_js_translate(array $files = array()) {
   $language_interface = language(Language::TYPE_INTERFACE);
 
-  $dir = 'public://' . Drupal::config('locale.settings')->get('javascript.directory');
-  $parsed = Drupal::state()->get('system.javascript_parsed') ?: array();
+  $dir = 'public://' . \Drupal::config('locale.settings')->get('javascript.directory');
+  $parsed = \Drupal::state()->get('system.javascript_parsed') ?: array();
   $new_files = FALSE;
 
   foreach ($files as $filepath) {
@@ -642,16 +642,16 @@ function locale_js_translate(array $files = array()) {
       unset($parsed['refresh:' . $language_interface->id]);
     }
     // Store any changes after refresh was attempted.
-    Drupal::state()->set('system.javascript_parsed', $parsed);
+    \Drupal::state()->set('system.javascript_parsed', $parsed);
   }
   // If no refresh was attempted, but we have new source files, we need
   // to store them too. This occurs if current page is in English.
   elseif ($new_files) {
-    Drupal::state()->set('system.javascript_parsed', $parsed);
+    \Drupal::state()->set('system.javascript_parsed', $parsed);
   }
 
   // Add the translation JavaScript file to the page.
-  $locale_javascripts = Drupal::state()->get('translation.javascript') ?: array();
+  $locale_javascripts = \Drupal::state()->get('translation.javascript') ?: array();
   $translation_file = NULL;
   if (!empty($files) && !empty($locale_javascripts[$language_interface->id])) {
     // Add the translation JavaScript file to the page.
@@ -666,7 +666,7 @@ function locale_js_translate(array $files = array()) {
 function locale_library_info() {
   $libraries['drupal.locale.admin'] = array(
     'title' => 'Locale',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'locale') . '/locale.admin.js' => array(),
     ),
@@ -678,7 +678,7 @@ function locale_library_info() {
   );
   $libraries['drupal.locale.datepicker'] = array(
     'title' => 'Locale Datepicker UI',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'locale') . '/locale.datepicker.js' => array(),
     ),
@@ -710,7 +710,7 @@ function locale_library_info_alter(&$libraries, $module) {
           'ui' => array(
             'datepicker' => array(
               'isRTL' => $language_interface->direction == Language::DIRECTION_RTL,
-              'firstDay' => Drupal::config('system.date')->get('first_day'),
+              'firstDay' => \Drupal::config('system.date')->get('first_day'),
             ),
           ),
         ),
@@ -726,12 +726,12 @@ function locale_library_info_alter(&$libraries, $module) {
 function locale_form_language_admin_overview_form_alter(&$form, &$form_state) {
   $languages = $form['languages']['#languages'];
 
-  $total_strings = Drupal::service('locale.storage')->countStrings();
+  $total_strings = \Drupal::service('locale.storage')->countStrings();
   $stats = array_fill_keys(array_keys($languages), array());
 
   // If we have source strings, count translations and calculate progress.
   if (!empty($total_strings)) {
-    $translations = Drupal::service('locale.storage')->countTranslations();
+    $translations = \Drupal::service('locale.storage')->countTranslations();
     foreach ($translations as $langcode => $translated) {
       $stats[$langcode]['translated'] = $translated;
       if ($translated > 0) {
@@ -787,7 +787,7 @@ function locale_form_language_admin_add_form_alter(&$form, &$form_state) {
  * Set a batch for a newly-added language.
  */
 function locale_form_language_admin_add_form_alter_submit($form, $form_state) {
-  if (Drupal::config('locale.settings')->get('translation.import_enabled')) {
+  if (\Drupal::config('locale.settings')->get('translation.import_enabled')) {
     if (empty($form_state['values']['predefined_langcode']) || $form_state['values']['predefined_langcode'] == 'custom') {
       $langcode = $form_state['values']['langcode'];
     }
@@ -802,7 +802,7 @@ function locale_form_language_admin_add_form_alter_submit($form, $form_state) {
     batch_set($batch);
 
     // Create or update all configuration translations for this language.
-    Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
+    \Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
     if ($batch = locale_config_batch_update_components($options, array($langcode))) {
       batch_set($batch);
     }
@@ -849,7 +849,7 @@ function locale_form_system_file_system_settings_alter(&$form, $form_state) {
   $form['translation_path'] = array(
     '#type' => 'textfield',
     '#title' => t('Interface translations directory'),
-    '#default_value' => Drupal::config('locale.settings')->get('translation.path'),
+    '#default_value' => \Drupal::config('locale.settings')->get('translation.path'),
     '#maxlength' => 255,
     '#description' => t('A local file system path where interface translation files will be stored.'),
     '#required' => TRUE,
@@ -874,7 +874,7 @@ function locale_system_file_system_settings_submit(&$form, $form_state) {
     locale_translation_clear_status();
   }
 
-  Drupal::config('locale.settings')
+  \Drupal::config('locale.settings')
     ->set('translation.path', $form_state['values']['translation_path'])
     ->save();
 }
@@ -975,7 +975,7 @@ function locale_translation_file_history_delete($projects = array(), $langcodes
  */
 function locale_translation_get_status($projects = NULL, $langcodes = NULL) {
   $result = array();
-  $status = Drupal::state()->get('locale.translation_status');
+  $status = \Drupal::state()->get('locale.translation_status');
   module_load_include('translation.inc', 'locale');
   $projects = $projects ? $projects : array_keys(locale_translation_get_projects());
   $langcodes = $langcodes ? $langcodes : array_keys(locale_translatable_language_list());
@@ -1052,8 +1052,8 @@ function locale_translation_status_save($project, $langcode, $type, $data) {
         break;
     }
 
-    Drupal::state()->set('locale.translation_status', $status);
-    Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
+    \Drupal::state()->set('locale.translation_status', $status);
+    \Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
   }
 }
 
@@ -1072,7 +1072,7 @@ function locale_translation_status_delete_languages($langcodes) {
         }
       }
     }
-    Drupal::state()->set('locale.translation_status', $status);
+    \Drupal::state()->set('locale.translation_status', $status);
   }
 }
 
@@ -1090,15 +1090,15 @@ function locale_translation_status_delete_projects($projects) {
       unset($status[$project]);
     }
   }
-  Drupal::state()->set('locale.translation_status', $status);
+  \Drupal::state()->set('locale.translation_status', $status);
 }
 
 /**
  * Clear the translation status cache.
  */
 function locale_translation_clear_status() {
-  Drupal::state()->delete('locale.translation_status');
-  Drupal::state()->delete('locale.translation_last_checked');
+  \Drupal::state()->delete('locale.translation_status');
+  \Drupal::state()->delete('locale.translation_last_checked');
 }
 
 /**
@@ -1109,7 +1109,7 @@ function locale_translation_clear_status() {
  *   when checking or importing translation files, FALSE otherwise.
  */
 function locale_translation_use_remote_source() {
-  return Drupal::config('locale.settings')->get('translation.use_source') == LOCALE_TRANSLATION_USE_SOURCE_REMOTE_AND_LOCAL;
+  return \Drupal::config('locale.settings')->get('translation.use_source') == LOCALE_TRANSLATION_USE_SOURCE_REMOTE_AND_LOCAL;
 }
 
 /**
@@ -1147,7 +1147,7 @@ function _locale_refresh_translations($langcodes, $lids = array()) {
   if (!empty($langcodes)) {
     // Update javascript translations if any of the strings has a javascript
     // location, or if no string ids were provided, update all languages.
-    if (empty($lids) || ($strings = Drupal::service('locale.storage')->getStrings(array('lid' => $lids, 'type' => 'javascript')))) {
+    if (empty($lids) || ($strings = \Drupal::service('locale.storage')->getStrings(array('lid' => $lids, 'type' => 'javascript')))) {
       array_map('_locale_invalidate_js', $langcodes);
     }
   }
@@ -1169,7 +1169,7 @@ function _locale_refresh_translations($langcodes, $lids = array()) {
  */
 function _locale_refresh_configuration(array $langcodes, array $lids) {
   if ($lids && $langcodes && $names = \Drupal\locale\Locale::config()->getStringNames($lids)) {
-    Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
+    \Drupal::moduleHandler()->loadInclude('locale', 'bulk.inc');
     locale_config_update_multiple($names, $langcodes);
   }
 }
@@ -1267,11 +1267,11 @@ function _locale_parse_js_file($filepath) {
     $string =  implode('', preg_split('~(?<!\\\\)[\'"]\s*\+\s*[\'"]~s', substr($match['string'], 1, -1)));
     $context = implode('', preg_split('~(?<!\\\\)[\'"]\s*\+\s*[\'"]~s', substr($match['context'], 1, -1)));
 
-    $source = Drupal::service('locale.storage')->findString(array('source' => $string, 'context' => $context));
+    $source = \Drupal::service('locale.storage')->findString(array('source' => $string, 'context' => $context));
 
     if (!$source) {
       // We don't have the source string yet, thus we insert it into the database.
-      $source = Drupal::service('locale.storage')->createString(array(
+      $source = \Drupal::service('locale.storage')->createString(array(
         'source'    => $string,
         'context'   => $context,
       ));
@@ -1297,7 +1297,7 @@ function _locale_parse_js_file($filepath) {
  *   New content of the 'system.javascript_parsed' variable.
  */
 function _locale_invalidate_js($langcode = NULL) {
-  $parsed = Drupal::state()->get('system.javascript_parsed') ?: array();
+  $parsed = \Drupal::state()->get('system.javascript_parsed') ?: array();
 
   if (empty($langcode)) {
     // Invalidate all languages.
@@ -1311,7 +1311,7 @@ function _locale_invalidate_js($langcode = NULL) {
     $parsed['refresh:' . $langcode] = 'waiting';
   }
 
-  Drupal::state()->set('system.javascript_parsed', $parsed);
+  \Drupal::state()->set('system.javascript_parsed', $parsed);
   return $parsed;
 }
 
@@ -1322,7 +1322,7 @@ function _locale_invalidate_js($langcode = NULL) {
  *   The language, the translation file should be (re)created for.
  */
 function _locale_rebuild_js($langcode = NULL) {
-  $config = Drupal::config('locale.settings');
+  $config = \Drupal::config('locale.settings');
   if (!isset($langcode)) {
     $language = language(Language::TYPE_INTERFACE);
   }
@@ -1340,7 +1340,7 @@ function _locale_rebuild_js($langcode = NULL) {
     'translated' => TRUE,
   );
   $translations = array();
-  foreach (Drupal::service('locale.storage')->getTranslations($conditions) as $data) {
+  foreach (\Drupal::service('locale.storage')->getTranslations($conditions) as $data) {
     $translations[$data->context][$data->source] = $data->translation;
   }
 
@@ -1350,7 +1350,7 @@ function _locale_rebuild_js($langcode = NULL) {
   if (!empty($translations)) {
 
     $data = "Drupal.locale = { ";
-    $locale_plurals = Drupal::state()->get('locale.translation.plurals') ?: array();
+    $locale_plurals = \Drupal::state()->get('locale.translation.plurals') ?: array();
     if (!empty($locale_plurals[$language->id])) {
       $data .= "'pluralFormula': function (\$n) { return Number({$locale_plurals[$language->id]['formula']}); }, ";
     }
@@ -1364,7 +1364,7 @@ function _locale_rebuild_js($langcode = NULL) {
   $dir = 'public://' . $config->get('javascript.directory');
 
   // Delete old file, if we have no translations anymore, or a different file to be saved.
-  $locale_javascripts = Drupal::state()->get('locale.translation.javascript') ?: array();
+  $locale_javascripts = \Drupal::state()->get('locale.translation.javascript') ?: array();
   $changed_hash = !isset($locale_javascripts[$language->id]) || ($locale_javascripts[$language->id] != $data_hash);
   if (!empty($locale_javascripts[$language->id]) && (!$data || $changed_hash)) {
     file_unmanaged_delete($dir . '/' . $language->id . '_' . $locale_javascripts[$language->id] . '.js');
@@ -1408,7 +1408,7 @@ function _locale_rebuild_js($langcode = NULL) {
   // deleted). Act only if some operation was executed that changed the hash
   // code.
   if ($status && $changed_hash) {
-    Drupal::state()->set('locale.translation.javascript', $locale_javascripts);
+    \Drupal::state()->set('locale.translation.javascript', $locale_javascripts);
   }
 
   // Log the operation and return success flag.
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index fbc5c598edfa8e0e810ef33e3c4a0e9b684dd757..1e045fe91da9bba1db47cac97a1552724d0520aa 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -112,7 +112,7 @@ function locale_translation_status_form($form, &$form_state) {
     });
   }
 
-  $last_checked = Drupal::state()->get('locale.translation_last_checked');
+  $last_checked = \Drupal::state()->get('locale.translation_last_checked');
   $form['last_checked'] = array(
     '#theme' => 'locale_translation_last_check',
     '#last' => $last_checked,
@@ -197,7 +197,7 @@ function locale_translation_status_form_submit($form, &$form_state) {
   // If the status was updated recently we can immediately start fetching the
   // translation updates. If the status is expired we clear it an run a batch to
   // update the status and then fetch the translation updates.
-  $last_checked = Drupal::state()->get('locale.translation_last_checked');
+  $last_checked = \Drupal::state()->get('locale.translation_last_checked');
   if ($last_checked < REQUEST_TIME - LOCALE_TRANSLATION_STATUS_TTL) {
     locale_translation_clear_status();
     $batch = locale_translation_batch_update_build(array(), $langcodes, $options);
diff --git a/core/modules/locale/locale.translation.inc b/core/modules/locale/locale.translation.inc
index 30c7b0f27879e7edf8884d8fd780b869669f727c..bb915428b2fadf4df1d97963b4951551988e5913 100644
--- a/core/modules/locale/locale.translation.inc
+++ b/core/modules/locale/locale.translation.inc
@@ -58,7 +58,7 @@ function locale_translation_get_projects($project_names = array()) {
 
     // http://drupal.org/node/1777106 is a follow-up issue to make the check for
     // possible out-of-date project information more robust.
-    if ($result->rowCount() == 0 && Drupal::moduleHandler()->moduleExists('update')) {
+    if ($result->rowCount() == 0 && \Drupal::moduleHandler()->moduleExists('update')) {
       module_load_include('compare.inc', 'locale');
       // At least the core project should be in the database, so we build the
       // data if none are found.
@@ -236,7 +236,7 @@ function locale_translation_source_build($project, $langcode, $filename = NULL)
   $source->timestamp = 0;
   $source->last_checked = 0;
 
-  $filename = $filename ? $filename : Drupal::config('locale.settings')->get('translation.default_filename');
+  $filename = $filename ? $filename : \Drupal::config('locale.settings')->get('translation.default_filename');
 
   // If the server_pattern contains a remote file path we will check for a
   // remote file. The local version of this file will only be checked if a
@@ -322,7 +322,7 @@ function locale_translation_build_server_pattern($project, $template) {
  */
 function locale_cron_fill_queue() {
   $updates = array();
-  $config = Drupal::config('locale.settings');
+  $config = \Drupal::config('locale.settings');
 
   // Determine which project+language should be updated.
   $last = REQUEST_TIME - $config->get('translation.update_interval_days') * 3600 * 24;
@@ -351,7 +351,7 @@ function locale_cron_fill_queue() {
   if ($updates) {
     module_load_include('fetch.inc', 'locale');
     $options = _locale_translation_default_update_options();
-    $queue = Drupal::queue('locale_translation', TRUE);
+    $queue = \Drupal::queue('locale_translation', TRUE);
 
     foreach ($updates as $project => $languages) {
       $batch = locale_translation_batch_update_build(array($project), $languages, $options);
@@ -425,7 +425,7 @@ function _locale_translation_source_compare($source1, $source2) {
  *   Array of translation import options.
  */
 function _locale_translation_default_update_options() {
-  $config = Drupal::config('locale.settings');
+  $config = \Drupal::config('locale.settings');
   return array(
     'customized' => LOCALE_NOT_CUSTOMIZED,
     'overwrite_options' => array(
diff --git a/core/modules/locale/tests/modules/locale_test/locale_test.install b/core/modules/locale/tests/modules/locale_test/locale_test.install
index e820b9f9eb09d846137111ebbce227af5d872037..be5ad52b6b3105f39079b661e43e3b2e09888a39 100644
--- a/core/modules/locale/tests/modules/locale_test/locale_test.install
+++ b/core/modules/locale/tests/modules/locale_test/locale_test.install
@@ -10,6 +10,6 @@
  */
 function locale_test_uninstall() {
   // Clear variables.
-  Drupal::state()->delete('locale.test_system_info_alter');
-  Drupal::state()->delete('locale.test_projects_alter');
+  \Drupal::state()->delete('locale.test_system_info_alter');
+  \Drupal::state()->delete('locale.test_projects_alter');
 }
diff --git a/core/modules/locale/tests/modules/locale_test/locale_test.module b/core/modules/locale/tests/modules/locale_test/locale_test.module
index 6de4ce627fd37cf509552925bc7596f2ed4e0ac2..166983aaef5ceec54626381c99c285ebb327957f 100644
--- a/core/modules/locale/tests/modules/locale_test/locale_test.module
+++ b/core/modules/locale/tests/modules/locale_test/locale_test.module
@@ -17,7 +17,7 @@ function locale_test_system_info_alter(&$info, $file, $type) {
   // By default the locale_test modules are hidden and have a project specified.
   // To test the module detection proces by locale_project_list() the
   // test modules should mimic a custom module. I.e. be non-hidden.
-  if (Drupal::state()->get('locale.test_system_info_alter')) {
+  if (\Drupal::state()->get('locale.test_system_info_alter')) {
     if ($file->name == 'locale_test' || $file->name == 'locale_test_translate') {
       // Don't hide the module.
       $info['hidden'] = FALSE;
@@ -38,7 +38,7 @@ function locale_test_system_info_alter(&$info, $file, $type) {
  * test script in order for this hook to take effect.
  */
 function locale_test_locale_translation_projects_alter(&$projects) {
-  if (Drupal::state()->get('locale.test_projects_alter')) {
+  if (\Drupal::state()->get('locale.test_projects_alter')) {
 
     // Instead of the default ftp.drupal.org we use the file system of the test
     // instance to simulate a remote file location.
diff --git a/core/modules/menu/menu.install b/core/modules/menu/menu.install
index 36e6302a7b6b46190e2327974fadf3533e221b14..ac395f92d24a422b5470464a5b4ad9f5dbec02e4 100644
--- a/core/modules/menu/menu.install
+++ b/core/modules/menu/menu.install
@@ -80,7 +80,7 @@ function menu_update_8004() {
   $result = db_query('SELECT * FROM {menu_custom}');
   foreach ($result as $menu) {
     // Save the config object.
-    Drupal::config('system.menu.' . $menu->menu_name)
+    \Drupal::config('system.menu.' . $menu->menu_name)
       ->set('id', $menu->menu_name)
       ->set('uuid', $uuid->generate())
       ->set('label', $menu->title)
diff --git a/core/modules/menu/menu.module b/core/modules/menu/menu.module
index 038177a038e59aaae46b9452b6c04a20a37838ba..08355a100387d22d3c83027fcd4055c6367e67a5 100644
--- a/core/modules/menu/menu.module
+++ b/core/modules/menu/menu.module
@@ -143,7 +143,7 @@ function menu_entity_bundle_info() {
   $bundles = array();
   $config_names = config_get_storage_names_with_prefix('system.menu.');
   foreach ($config_names as $config_name) {
-    $config = Drupal::config($config_name);
+    $config = \Drupal::config($config_name);
     $bundles['menu_link'][$config->get('id')] = array(
       'label' => $config->get('label'),
     );
@@ -182,7 +182,7 @@ function menu_theme() {
  * Add a link for each custom menu.
  */
 function menu_enable() {
-  Drupal::service('router.builder')->rebuild();
+  \Drupal::service('router.builder')->rebuild();
   menu_router_rebuild();
   $system_link = entity_load_multiple_by_properties('menu_link', array('link_path' => 'admin/structure/menu', 'module' => 'system'));
   $system_link = reset($system_link);
@@ -200,7 +200,7 @@ function menu_enable() {
     $link->link_title = $menu->label();
     $link->link_path = 'admin/structure/menu/manage/' . $menu->id();
 
-    $query = Drupal::entityQuery('menu_link')
+    $query = \Drupal::entityQuery('menu_link')
       ->condition('link_path', $link->link_path)
       ->condition('plid', $link->plid);
     $result = $query->execute();
@@ -231,12 +231,12 @@ function menu_menu_insert(Menu $menu) {
   menu_cache_clear_all();
   // Invalidate the block cache to update menu-based derivatives.
   if (module_exists('block')) {
-    Drupal::service('plugin.manager.block')->clearCachedDefinitions();
+    \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
   }
   // Make sure the menu is present in the active menus variable so that its
   // items may appear in the menu active trail.
   // See menu_set_active_menu_names().
-  $config = Drupal::config('system.menu');
+  $config = \Drupal::config('system.menu');
 
   $active_menus = $config->get('active_menus_default') ?: array_keys(menu_get_menus());
   if (!in_array($menu->id(), $active_menus)) {
@@ -254,7 +254,7 @@ function menu_menu_update(Menu $menu) {
   menu_cache_clear_all();
   // Invalidate the block cache to update menu-based derivatives.
   if (module_exists('block')) {
-    Drupal::service('plugin.manager.block')->clearCachedDefinitions();
+    \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
   }
 }
 
@@ -283,7 +283,7 @@ function menu_menu_delete(Menu $menu) {
 
   // Invalidate the block cache to update menu-based derivatives.
   if (module_exists('block')) {
-    Drupal::service('plugin.manager.block')->clearCachedDefinitions();
+    \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
   }
 }
 
@@ -312,7 +312,7 @@ function menu_parent_options(array $menus, MenuLink $menu_link = NULL, $type = N
   // allow contrib modules to provide more scalable pattern choosers.
   // hook_form_alter is too late in itself because all the possible parents are
   // retrieved here, unless override_parent_selector is set to TRUE.
-  if (Drupal::config('menu.settings')->get('override_parent_selector')) {
+  if (\Drupal::config('menu.settings')->get('override_parent_selector')) {
     return array();
   }
 
@@ -444,7 +444,7 @@ function menu_node_save(EntityInterface $node) {
  */
 function menu_node_predelete(EntityInterface $node) {
   // Delete all menu module links that point to this node.
-  $query = Drupal::entityQuery('menu_link')
+  $query = \Drupal::entityQuery('menu_link')
     ->condition('link_path', 'node/' . $node->id())
     ->condition('module', 'menu');
   $result = $query->execute();
@@ -467,7 +467,7 @@ function menu_node_prepare_form(NodeInterface $node, $form_display, $operation,
       // Give priority to the default menu
       $type_menus = variable_get('menu_options_' . $node->getType(), array('main' => 'main'));
       if (in_array($menu_name, $type_menus)) {
-        $query = Drupal::entityQuery('menu_link')
+        $query = \Drupal::entityQuery('menu_link')
           ->condition('link_path', 'node/' . $node->id())
           ->condition('menu_name', $menu_name)
           ->condition('module', 'menu')
@@ -479,7 +479,7 @@ function menu_node_prepare_form(NodeInterface $node, $form_display, $operation,
       }
       // Check all allowed menus if a link does not exist in the default menu.
       if (!$mlid && !empty($type_menus)) {
-        $query = Drupal::entityQuery('menu_link')
+        $query = \Drupal::entityQuery('menu_link')
           ->condition('link_path', 'node/' . $node->id())
           ->condition('menu_name', array_values($type_menus), 'IN')
           ->condition('module', 'menu')
@@ -714,7 +714,7 @@ function menu_preprocess_block(&$variables) {
 function menu_library_info() {
   $libraries['drupal.menu'] = array(
     'title' => 'Menu',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'menu') . '/menu.js' => array(),
     ),
@@ -726,7 +726,7 @@ function menu_library_info() {
   );
   $libraries['drupal.menu.admin'] = array(
     'title' => 'Menu admin',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'menu') . '/menu.admin.js' => array(),
     ),
diff --git a/core/modules/menu_link/menu_link.module b/core/modules/menu_link/menu_link.module
index 105e502d20234f11949aa6f0095a0da4743bac27..85d8e92c012a3c73fc6b9c1032c4e081aacfdd0a 100644
--- a/core/modules/menu_link/menu_link.module
+++ b/core/modules/menu_link/menu_link.module
@@ -96,10 +96,10 @@ function menu_link_delete_multiple(array $mlids, $force = FALSE, $prevent_repare
     return;
   }
 
-  $controller = Drupal::entityManager()
+  $controller = \Drupal::entityManager()
     ->getStorageController('menu_link');
   if (!$force) {
-    $entity_query = Drupal::entityQuery('menu_link');
+    $entity_query = \Drupal::entityQuery('menu_link');
     $group = $entity_query->orConditionGroup()
       ->condition('module', 'system', '<>')
       ->condition('updated', 0, '<>');
@@ -151,7 +151,7 @@ function menu_link_save(MenuLink $menu_link) {
  *   The insert op returns the mlid of the new item. Others op return NULL.
  */
 function menu_link_maintain($module, $op, $link_path, $link_title = NULL) {
-  $menu_link_controller = Drupal::entityManager()
+  $menu_link_controller = \Drupal::entityManager()
     ->getStorageController('menu_link');
   switch ($op) {
     case 'insert':
@@ -188,7 +188,7 @@ function menu_link_maintain($module, $op, $link_path, $link_title = NULL) {
       break;
 
     case 'delete':
-      $result = Drupal::entityQuery('menu_link')->condition('link_path', $link_path)->execute();
+      $result = \Drupal::entityQuery('menu_link')->condition('link_path', $link_path)->execute();
       if (!empty($result)) {
         menu_link_delete_multiple($result);
       }
diff --git a/core/modules/node/node.install b/core/modules/node/node.install
index 02cc7a01a9c6e7e23ca10f89a568f4a243242ba3..7fb28bf1c6c02d18887e9a400eaf93e5defcf4d9 100644
--- a/core/modules/node/node.install
+++ b/core/modules/node/node.install
@@ -418,8 +418,8 @@ function node_uninstall() {
   // Delete node type variables.
   $types = config_get_storage_names_with_prefix('node.type.');
   foreach ($types as $config_name) {
-    $type = Drupal::config($config_name)->get('type');
-    Drupal::config('language.settings')->clear('node. ' . $type . '.language.default_configuration')->save();
+    $type = \Drupal::config($config_name)->get('type');
+    \Drupal::config('language.settings')->clear('node. ' . $type . '.language.default_configuration')->save();
   }
 
   // Delete node search ranking variables.
@@ -429,11 +429,11 @@ function node_uninstall() {
   variable_del('node_rank_recent');
 
   // Delete remaining general module variables.
-  Drupal::state()->delete('node.node_access_needs_rebuild');
+  \Drupal::state()->delete('node.node_access_needs_rebuild');
   variable_del('node_recent_block_count');
 
   // Delete any stored state.
-  Drupal::state()->delete('node.cron_last');
+  \Drupal::state()->delete('node.cron_last');
 }
 
 /**
@@ -639,7 +639,7 @@ function node_update_8007() {
     $language_show = update_variable_get('node_type_language_show_' . $type, NULL);
     if (isset($language_default) || isset($language_show)) {
       $values = array('langcode' => $language_default, 'language_show' => $language_show);
-      Drupal::config('language.settings')->set('node.' . $type . '.language.default_configuration', $values)->save();
+      \Drupal::config('language.settings')->set('node.' . $type . '.language.default_configuration', $values)->save();
     }
   }
 }
@@ -1075,7 +1075,7 @@ function node_update_8020() {
   $result = db_query('SELECT * FROM {node_type}')
     ->fetchAllAssoc('type', PDO::FETCH_ASSOC);
   foreach ($result as $id => $node_type) {
-    $config = Drupal::config('node.type.' . $id);
+    $config = \Drupal::config('node.type.' . $id);
     // Node type.
     $config->setData($node_type);
     $config->set('uuid', $uuid->generate());
@@ -1110,7 +1110,7 @@ function node_update_8020() {
       $locked[$id] = $node_type['base'];
     }
   }
-  Drupal::state()->set('node.type.locked', $locked);
+  \Drupal::state()->set('node.type.locked', $locked);
 }
 
 /**
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index 8c6eddb43e8599d1b3fd1d137e20d108dd2b5407..ca8d316833ab2cf9caf3c52055b2760f9d506ef3 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -220,7 +220,7 @@ function node_uri(EntityInterface $node) {
  * Implements hook_admin_paths().
  */
 function node_admin_paths() {
-  if (Drupal::config('node.settings')->get('use_admin_theme')) {
+  if (\Drupal::config('node.settings')->get('use_admin_theme')) {
     $paths = array(
       'node/*/edit' => TRUE,
       'node/*/delete' => TRUE,
@@ -326,7 +326,7 @@ function node_type_get_names() {
   $config_names = config_get_storage_names_with_prefix('node.type.');
   $names = array();
   foreach ($config_names as $config_name) {
-    $config = Drupal::config($config_name);
+    $config = \Drupal::config($config_name);
     $names[$config->get('type')] = $config->get('name');
   }
   cache()->set($cid, $names, CacheBackendInterface::CACHE_PERMANENT, array(
@@ -586,7 +586,7 @@ function node_show(EntityInterface $node, $message = FALSE) {
 
   // Update the history table, stating that this user viewed this node.
   global $user;
-  if (Drupal::moduleHandler()->moduleExists('history') && $user->isAuthenticated()) {
+  if (\Drupal::moduleHandler()->moduleExists('history') && $user->isAuthenticated()) {
     $page['#attached'] = array(
       'js' => array(
         // When the window's "load" event is triggered, mark the node as read.
@@ -684,7 +684,7 @@ function template_preprocess_node(&$variables) {
 
   // Display post information only on certain node types.
   // Avoid loading the entire node type config entity here.
-  $submitted = Drupal::config('node.type.' . $node->bundle())->get('settings.node.submitted') ?: TRUE;
+  $submitted = \Drupal::config('node.type.' . $node->bundle())->get('settings.node.submitted') ?: TRUE;
   if ($submitted) {
     $variables['display_submitted'] = TRUE;
     $variables['submitted'] = t('Submitted by !username on !datetime', array('!username' => $variables['name'], '!datetime' => $variables['date']));
@@ -808,7 +808,7 @@ function node_ranking() {
   );
 
   // Add relevance based on creation or changed date.
-  if ($node_cron_last = Drupal::state()->get('node.cron_last')) {
+  if ($node_cron_last = \Drupal::state()->get('node.cron_last')) {
     $ranking['recent'] = array(
       'title' => t('Recently posted'),
       // Exponential decay with half-life of 6 months, starting at last indexed node
@@ -931,7 +931,7 @@ function theme_node_search_admin($variables) {
  * @see node_menu()
  */
 function _node_revision_access(EntityInterface $node, $op = 'view', $account = NULL, $langcode = NULL) {
-  return Drupal::service('access_check.node.revision')->checkAccess($node, $op, $account, $langcode);
+  return \Drupal::service('access_check.node.revision')->checkAccess($node, $op, $account, $langcode);
 }
 
 /**
@@ -1308,7 +1308,7 @@ function node_modules_uninstalled($modules) {
   // Remove module-specific settings from all node types.
   $config_names = config_get_storage_names_with_prefix('node.type.');
   foreach ($config_names as $config_name) {
-    $config = Drupal::config($config_name);
+    $config = \Drupal::config($config_name);
     $changed = FALSE;
     foreach ($modules as $module) {
       if ($config->get('settings.' . $module)) {
@@ -1391,7 +1391,7 @@ function node_block_access($block) {
 function node_feed($nids = FALSE, $channel = array()) {
   global $base_url;
   $language_content = language(Language::TYPE_CONTENT);
-  $rss_config = Drupal::config('system.rss');
+  $rss_config = \Drupal::config('system.rss');
 
   if ($nids === FALSE) {
     $nids = db_select('node_field_data', 'n')
@@ -1443,7 +1443,7 @@ function node_feed($nids = FALSE, $channel = array()) {
 
   $channel_defaults = array(
     'version'     => '2.0',
-    'title'       => Drupal::config('system.site')->get('name'),
+    'title'       => \Drupal::config('system.site')->get('name'),
     'link'        => $base_url,
     'description' => $rss_config->get('channel.description'),
     'language'    => $language_content->id
@@ -1540,9 +1540,9 @@ function node_form_system_site_information_settings_form_alter(&$form, &$form_st
   $form['front_page']['default_nodes_main'] = array(
     '#type' => 'select',
     '#title' => t('Number of posts on front page'),
-    '#default_value' => Drupal::config('node.settings')->get('items_per_page'),
+    '#default_value' => \Drupal::config('node.settings')->get('items_per_page'),
     '#options' => drupal_map_assoc(array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30)),
-    '#access' => (Drupal::config('system.site')->get('page.front') == 'node'),
+    '#access' => (\Drupal::config('system.site')->get('page.front') == 'node'),
     '#description' => t('The maximum number of posts displayed on overview pages such as the front page.'),
   );
   $form['#submit'][] = 'node_form_system_site_information_settings_form_submit';
@@ -1554,7 +1554,7 @@ function node_form_system_site_information_settings_form_alter(&$form, &$form_st
  * @see node_form_system_site_information_settings_form_alter()
  */
 function node_form_system_site_information_settings_form_submit($form, &$form_state) {
-  Drupal::config('node.settings')
+  \Drupal::config('node.settings')
     ->set('items_per_page', $form_state['values']['default_nodes_main'])
     ->save();
 }
@@ -1570,7 +1570,7 @@ function node_form_system_themes_admin_form_alter(&$form, &$form_state, $form_id
   $form['admin_theme']['use_admin_theme'] = array(
     '#type' => 'checkbox',
     '#title' => t('Use the administration theme when editing or creating content'),
-    '#default_value' => Drupal::config('node.settings')->get('use_admin_theme'),
+    '#default_value' => \Drupal::config('node.settings')->get('use_admin_theme'),
   );
   $form['#submit'][] = 'node_form_system_themes_admin_form_submit';
 }
@@ -1581,7 +1581,7 @@ function node_form_system_themes_admin_form_alter(&$form, &$form_state, $form_id
  * @see node_form_system_themes_admin_form_alter()
  */
 function node_form_system_themes_admin_form_submit($form, &$form_state) {
-  Drupal::config('node.settings')
+  \Drupal::config('node.settings')
     ->set('use_admin_theme', $form_state['values']['use_admin_theme'])
     ->save();
 }
@@ -1656,7 +1656,7 @@ function node_form_system_themes_admin_form_submit($form, &$form_state) {
  * @see node_menu()
  */
 function node_access($op, $node, $account = NULL, $langcode = NULL) {
-  $access_controller = Drupal::entityManager()->getAccessController('node');
+  $access_controller = \Drupal::entityManager()->getAccessController('node');
 
   if ($op == 'create') {
     if (!$node instanceof EntityInterface) {
@@ -1801,7 +1801,7 @@ function node_access_grants($op, $account = NULL) {
   }
 
   // Fetch node access grants from other modules.
-  $grants = Drupal::moduleHandler()->invokeAll('node_grants', array($account, $op));
+  $grants = \Drupal::moduleHandler()->invokeAll('node_grants', array($account, $op));
   // Allow modules to alter the assigned grants.
   drupal_alter('node_grants', $grants, $account, $op);
 
@@ -1843,11 +1843,11 @@ function node_access_view_all_nodes($account = NULL) {
   }
 
   // If no modules implement the node access system, access is always TRUE.
-  if (!Drupal::moduleHandler()->getImplementations('node_grants')) {
+  if (!\Drupal::moduleHandler()->getImplementations('node_grants')) {
     $access[$account->id()] = TRUE;
   }
   else {
-    $access[$account->id()] = Drupal::entityManager()->getAccessController('node')->checkAllGrants($account);
+    $access[$account->id()] = \Drupal::entityManager()->getAccessController('node')->checkAllGrants($account);
   }
 
   return $access[$account->id()];
@@ -1887,7 +1887,7 @@ function node_query_node_access_alter(AlterableInterface $query) {
   if (user_access('bypass node access', $account)) {
     return;
   }
-  if (!count(Drupal::moduleHandler()->getImplementations('node_grants'))) {
+  if (!count(\Drupal::moduleHandler()->getImplementations('node_grants'))) {
     return;
   }
   if ($op == 'view' && node_access_view_all_nodes($account)) {
@@ -1915,7 +1915,7 @@ function node_query_node_access_alter(AlterableInterface $query) {
   }
 
   // Update the query for the given storage method.
-  Drupal::service('node.grant_storage')->alterQuery($query, $tables, $op, $account, $base_table);
+  \Drupal::service('node.grant_storage')->alterQuery($query, $tables, $op, $account, $base_table);
 }
 
 /**
@@ -1940,13 +1940,13 @@ function node_query_node_access_alter(AlterableInterface $query) {
  */
 function node_access_needs_rebuild($rebuild = NULL) {
   if (!isset($rebuild)) {
-    return Drupal::state()->get('node.node_access_needs_rebuild') ?: FALSE;
+    return \Drupal::state()->get('node.node_access_needs_rebuild') ?: FALSE;
   }
   elseif ($rebuild) {
-    Drupal::state()->set('node.node_access_needs_rebuild', TRUE);
+    \Drupal::state()->set('node.node_access_needs_rebuild', TRUE);
   }
   else {
-    Drupal::state()->delete('node.node_access_needs_rebuild');
+    \Drupal::state()->delete('node.node_access_needs_rebuild');
   }
 }
 
@@ -1973,10 +1973,10 @@ function node_access_needs_rebuild($rebuild = NULL) {
  * @see node_access_needs_rebuild()
  */
 function node_access_rebuild($batch_mode = FALSE) {
-  $access_controller = Drupal::entityManager()->getAccessController('node');
+  $access_controller = \Drupal::entityManager()->getAccessController('node');
   $access_controller->deleteGrants();
   // Only recalculate if the site is using a node_access module.
-  if (count(Drupal::moduleHandler()->getImplementations('node_grants'))) {
+  if (count(\Drupal::moduleHandler()->getImplementations('node_grants'))) {
     if ($batch_mode) {
       $batch = array(
         'title' => t('Rebuilding content access permissions'),
@@ -1992,7 +1992,7 @@ function node_access_rebuild($batch_mode = FALSE) {
       drupal_set_time_limit(240);
 
       // Rebuild newest nodes first so that recent content becomes available quickly.
-      $entity_query = Drupal::entityQuery('node');
+      $entity_query = \Drupal::entityQuery('node');
       $entity_query->sort('nid', 'DESC');
       $nids = $entity_query->execute();
       foreach ($nids as $nid) {
@@ -2032,12 +2032,12 @@ function _node_access_rebuild_batch_operation(&$context) {
     // Initiate multistep processing.
     $context['sandbox']['progress'] = 0;
     $context['sandbox']['current_node'] = 0;
-    $context['sandbox']['max'] = Drupal::entityQuery('node')->count()->execute();
+    $context['sandbox']['max'] = \Drupal::entityQuery('node')->count()->execute();
   }
 
   // Process the next 20 nodes.
   $limit = 20;
-  $nids = Drupal::entityQuery('node')
+  $nids = \Drupal::entityQuery('node')
     ->condition('nid', $context['sandbox']['current_node'], '>')
     ->sort('nid', 'DESC')
     ->range(0, $limit)
@@ -2047,7 +2047,7 @@ function _node_access_rebuild_batch_operation(&$context) {
     // To preserve database integrity, only write grants if the node
     // loads successfully.
     if (!empty($node)) {
-      Drupal::entityManager()->getAccessController('node')->writeGrants($node);
+      \Drupal::entityManager()->getAccessController('node')->writeGrants($node);
     }
     $context['sandbox']['progress']++;
     $context['sandbox']['current_node'] = $nid;
@@ -2093,8 +2093,8 @@ function node_requirements($phase) {
     // Only show rebuild button if there are either 0, or 2 or more, rows
     // in the {node_access} table, or if there are modules that
     // implement hook_node_grants().
-    $grant_count = Drupal::entityManager()->getAccessController('node')->countGrants();
-    if ($grant_count != 1 || count(Drupal::moduleHandler()->getImplementations('node_grants')) > 0) {
+    $grant_count = \Drupal::entityManager()->getAccessController('node')->countGrants();
+    if ($grant_count != 1 || count(\Drupal::moduleHandler()->getImplementations('node_grants')) > 0) {
       $value = format_plural($grant_count, 'One permission in use', '@count permissions in use', array('@count' => $grant_count));
     }
     else {
@@ -2117,7 +2117,7 @@ function node_requirements($phase) {
 function node_modules_enabled($modules) {
   // Check if any of the newly enabled modules require the node_access table to
   // be rebuilt.
-  if (!node_access_needs_rebuild() && array_intersect($modules, Drupal::moduleHandler()->getImplementations('node_grants'))) {
+  if (!node_access_needs_rebuild() && array_intersect($modules, \Drupal::moduleHandler()->getImplementations('node_grants'))) {
     node_access_needs_rebuild(TRUE);
   }
 }
@@ -2134,14 +2134,14 @@ function node_modules_disabled($modules) {
     // check whether a hook implementation function exists and do not invoke it.
     // Node access also needs to be rebuilt if language module is disabled to
     // remove any language-specific grants.
-    if (!node_access_needs_rebuild() && (Drupal::moduleHandler()->implementsHook($module, 'node_grants') || $module == 'language')) {
+    if (!node_access_needs_rebuild() && (\Drupal::moduleHandler()->implementsHook($module, 'node_grants') || $module == 'language')) {
       node_access_needs_rebuild(TRUE);
     }
   }
 
   // If there remains no more node_access module, rebuilding will be
   // straightforward, we can do it right now.
-  if (node_access_needs_rebuild() && count(Drupal::moduleHandler()->getImplementations('node_grants')) == 0) {
+  if (node_access_needs_rebuild() && count(\Drupal::moduleHandler()->getImplementations('node_grants')) == 0) {
     node_access_rebuild();
   }
 }
@@ -2172,7 +2172,7 @@ function node_language_delete($language) {
 function node_library_info() {
   $libraries['drupal.node'] = array(
     'title' => 'Node',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'node') . '/node.js' => array(),
     ),
@@ -2185,7 +2185,7 @@ function node_library_info() {
   );
   $libraries['drupal.node.preview'] = array(
     'title' => 'Node preview',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'node') . '/node.preview.js' => array(),
     ),
@@ -2196,7 +2196,7 @@ function node_library_info() {
   );
   $libraries['drupal.content_types'] = array(
     'title' => 'Content types',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'node') . '/content_types.js' => array(),
     ),
@@ -2222,7 +2222,7 @@ function node_library_info() {
  */
 function node_system_info_alter(&$info, $file, $type) {
   if ($type == 'module' && $file->name == 'translation') {
-    $info['hidden'] = !module_exists('translation') && Drupal::config('system.module.disabled')->get('translation') === NULL;
+    $info['hidden'] = !module_exists('translation') && \Drupal::config('system.module.disabled')->get('translation') === NULL;
   }
 }
 
@@ -2233,7 +2233,7 @@ function node_system_info_alter(&$info, $file, $type) {
  *   The node ID.
  */
 function node_reindex_node_search($nid) {
-  if (Drupal::moduleHandler()->moduleExists('search')) {
+  if (\Drupal::moduleHandler()->moduleExists('search')) {
     // Reindex node context indexed by the node module search plugin.
     search_mark_for_reindex('node_search', $nid);
   }
diff --git a/core/modules/node/node.pages.inc b/core/modules/node/node.pages.inc
index d80898e9ff4b9660697c4a325953346d2a747c19..1b6a1e57581579e113146ddbd00386e59c797af2 100644
--- a/core/modules/node/node.pages.inc
+++ b/core/modules/node/node.pages.inc
@@ -93,7 +93,7 @@ function node_add($node_type) {
     'langcode' => $langcode ? $langcode : language_default()->id,
   ));
   drupal_set_title(t('Create @name', array('@name' => $node_type->name)), PASS_THROUGH);
-  return Drupal::entityManager()->getForm($node);
+  return \Drupal::entityManager()->getForm($node);
 }
 
 /**
diff --git a/core/modules/node/node.tokens.inc b/core/modules/node/node.tokens.inc
index 397211f9fc0e29d4f51eab0aaa7cd9922ed0f23f..298d44eee6227db76d3804992438657646fb9a63 100644
--- a/core/modules/node/node.tokens.inc
+++ b/core/modules/node/node.tokens.inc
@@ -90,7 +90,7 @@ function node_token_info() {
  * Implements hook_tokens().
  */
 function node_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $url_options = array('absolute' => TRUE);
   if (isset($options['langcode'])) {
diff --git a/core/modules/node/node.views.inc b/core/modules/node/node.views.inc
index edd8ec4a376aa2784bc221627377a2edda5e1509..a3ad64340b5b16c85692fbc537be84f73d3d32cb 100644
--- a/core/modules/node/node.views.inc
+++ b/core/modules/node/node.views.inc
@@ -217,7 +217,7 @@ function node_views_data() {
     );
   }
 
-  if (Drupal::moduleHandler()->moduleExists('content_translation')) {
+  if (\Drupal::moduleHandler()->moduleExists('content_translation')) {
     $data['node']['translation_link'] = array(
       'title' => t('Translation link'),
       'help' => t('Provide a link to the translations overview for nodes.'),
diff --git a/core/modules/node/tests/modules/node_access_test/node_access_test.module b/core/modules/node/tests/modules/node_access_test/node_access_test.module
index abc18c6a635d45d8811bcbce064bd6b5b684baf9..793c5958af0286d65389da9aa871975fcce6fb02 100644
--- a/core/modules/node/tests/modules/node_access_test/node_access_test.module
+++ b/core/modules/node/tests/modules/node_access_test/node_access_test.module
@@ -23,7 +23,7 @@ function node_access_test_node_grants($account, $op) {
     $grants['node_access_test'] = array(8888, 8889);
   }
 
-  $no_access_uid = Drupal::state()->get('node_access_test.no_access_uid') ?: 0;
+  $no_access_uid = \Drupal::state()->get('node_access_test.no_access_uid') ?: 0;
   if ($op == 'view' && $account->id() == $no_access_uid) {
     $grants['node_access_all'] = array(0);
   }
@@ -36,7 +36,7 @@ function node_access_test_node_grants($account, $op) {
 function node_access_test_node_access_records(NodeInterface $node) {
   $grants = array();
   // For NodeAccessBaseTableTestCase, only set records for private nodes.
-  if (!Drupal::state()->get('node_access_test.private') || $node->private->value) {
+  if (!\Drupal::state()->get('node_access_test.private') || $node->private->value) {
     $grants[] = array(
       'realm' => 'node_access_test',
       'gid' => 8888,
@@ -97,7 +97,7 @@ function node_access_test_entity_field_info($entity_type) {
  */
 function node_access_test_form_node_form_alter(&$form, $form_state) {
   // Only show this checkbox for NodeAccessBaseTableTestCase.
-  if (Drupal::state()->get('node_access_test.private')) {
+  if (\Drupal::state()->get('node_access_test.private')) {
     $node = $form_state['controller']->getEntity($form_state);
     $form['private'] = array(
       '#type' => 'checkbox',
@@ -154,7 +154,7 @@ function _node_access_test_node_write(EntityInterface $node) {
  * Implements hook_node_access().
  */
 function node_access_test_node_access($node, $op, $account, $langcode) {
-  $secret_catalan = Drupal::state()->get('node_access_test_secret_catalan') ?: 0;
+  $secret_catalan = \Drupal::state()->get('node_access_test_secret_catalan') ?: 0;
   if ($secret_catalan && $langcode == 'ca') {
     // Make all Catalan content secret.
     return NODE_ACCESS_DENY;
diff --git a/core/modules/node/tests/modules/node_test/node_test.module b/core/modules/node/tests/modules/node_test/node_test.module
index 835f82cf97c40c5c680208c11cf54064356edae8..450f7034078551bb028d1362e99fd2495a196347 100644
--- a/core/modules/node/tests/modules/node_test/node_test.module
+++ b/core/modules/node/tests/modules/node_test/node_test.module
@@ -161,7 +161,7 @@ function node_test_node_update(EntityInterface $node) {
  */
 function node_test_entity_view_mode_alter(&$view_mode, Drupal\Core\Entity\EntityInterface $entity, $context) {
   // Only alter the view mode if we are on the test callback.
-  $change_view_mode = Drupal::state()->get( 'node_test_change_view_mode') ?: '';
+  $change_view_mode = \Drupal::state()->get( 'node_test_change_view_mode') ?: '';
   if ($change_view_mode) {
     $view_mode = $change_view_mode;
   }
@@ -186,7 +186,7 @@ function node_test_node_insert(EntityInterface $node) {
  * Implements hook_entity_info_alter().
  */
 function node_test_entity_info_alter(&$entity_info) {
-  if (Drupal::state()->get('node_test.storage_controller')) {
+  if (\Drupal::state()->get('node_test.storage_controller')) {
     $entity_info['node']['class'] = 'Drupal\node_test\NodeTest';
   }
 }
diff --git a/core/modules/options/options.module b/core/modules/options/options.module
index 6dedc1188ff3ae3e399af58d49c3081eb50c341b..3c649c502af731620ba0fe3a53176f5b66936ec2 100644
--- a/core/modules/options/options.module
+++ b/core/modules/options/options.module
@@ -383,7 +383,7 @@ function options_field_update_forbid($field, $prior_field) {
 function _options_values_in_use($field, $values) {
   if ($values) {
     $field = field_info_field_by_id($field['uuid']);
-    $factory = Drupal::service('entity.query');
+    $factory = \Drupal::service('entity.query');
     $result = $factory->get($field->entity_type)
       ->condition($field['field_name'] . '.value', $values)
       ->count()
diff --git a/core/modules/overlay/overlay.module b/core/modules/overlay/overlay.module
index 3788535208ed1bf37cf810c6eaca05b6a8b9c03e..b6194a8ae1611cd858e0f71b8fe160cbc58ff2c0 100644
--- a/core/modules/overlay/overlay.module
+++ b/core/modules/overlay/overlay.module
@@ -84,7 +84,7 @@ function overlay_field_extra_fields() {
 function overlay_form_user_form_alter(&$form, &$form_state) {
   $account = $form_state['controller']->getEntity();
   if ($account->hasPermission('access overlay')) {
-    $account_data = Drupal::service('user.data')->get('overlay', $account->id(), 'enabled');
+    $account_data = \Drupal::service('user.data')->get('overlay', $account->id(), 'enabled');
     $form['overlay_control'] = array(
       '#type' => 'details',
       '#title' => t('Administrative overlay'),
@@ -106,7 +106,7 @@ function overlay_form_user_form_alter(&$form, &$form_state) {
 function overlay_user_profile_form_submit($form, &$form_state) {
   $account = $form_state['controller']->getEntity();
   if ($account->id() && isset($form_state['values']['overlay'])) {
-    Drupal::service('user.data')->set('overlay', $account->id(), 'enabled', (int) $form_state['values']['overlay']);
+    \Drupal::service('user.data')->set('overlay', $account->id(), 'enabled', (int) $form_state['values']['overlay']);
   }
 }
 
@@ -223,7 +223,7 @@ function overlay_disable_message() {
     return $build;
   }
 
-  $user_data = Drupal::service('user.data')->get('overlay', $user->id());
+  $user_data = \Drupal::service('user.data')->get('overlay', $user->id());
   if (empty($user_data['message_dismissed']) && (!isset($user_data['enabled']) || $user_data['enabled'])) {
     $build = array(
       '#theme' => 'overlay_disable_message',
@@ -474,14 +474,14 @@ function overlay_set_mode($mode = NULL) {
       drupal_add_library('overlay', 'drupal.overlay.parent');
 
       // Allow modules to act upon overlay events.
-      Drupal::moduleHandler()->invokeAll('overlay_parent_initialize');
+      \Drupal::moduleHandler()->invokeAll('overlay_parent_initialize');
       break;
 
     case 'child':
       drupal_add_library('overlay', 'drupal.overlay.child');
 
       // Allow modules to act upon overlay events.
-      Drupal::moduleHandler()->invokeAll('overlay_child_initialize');
+      \Drupal::moduleHandler()->invokeAll('overlay_child_initialize');
       break;
   }
   return $overlay_mode;
@@ -494,13 +494,13 @@ function overlay_overlay_parent_initialize() {
   // Let the client side know which paths are administrative.
   $paths = path_get_admin_paths();
   foreach ($paths as &$type) {
-    $type = str_replace('<front>', Drupal::config('system.site')->get('page.front'), $type);
+    $type = str_replace('<front>', \Drupal::config('system.site')->get('page.front'), $type);
   }
   drupal_add_js(array('overlay' => array('paths' => $paths)), 'setting');
   $path_prefixes = array();
   if (module_exists('language')) {
     language_negotiation_include();
-    if (Drupal::config('language.negotiation')->get('url.source') == LANGUAGE_NEGOTIATION_URL_PREFIX) {
+    if (\Drupal::config('language.negotiation')->get('url.source') == LANGUAGE_NEGOTIATION_URL_PREFIX) {
       // Skip the empty string indicating the default language. We always accept
       // paths without a prefix.
       $path_prefixes = language_negotiation_url_prefixes();
@@ -527,8 +527,8 @@ function overlay_overlay_child_initialize() {
   // at the end of the page request. This allows us to check if anything
   // actually did change, and, if so, trigger an immediate Ajax refresh
   // of the parent window.
-  $token = Drupal::request()->query->get('token');
-  $post = Drupal::request()->request->count();
+  $token = \Drupal::request()->query->get('token');
+  $post = \Drupal::request()->request->count();
   if (!empty($post) || isset($token)) {
     foreach (overlay_supplemental_regions() as $region) {
       overlay_store_rendered_content($region, overlay_render_region($region));
diff --git a/core/modules/path/path.admin.inc b/core/modules/path/path.admin.inc
index b03f8d6a4ce8fd98e59e037ab10de8c8539e2453..200dbed1b9c154fb24805219bc11f800842c9319 100644
--- a/core/modules/path/path.admin.inc
+++ b/core/modules/path/path.admin.inc
@@ -77,7 +77,7 @@ function path_admin_overview($keys = NULL) {
 
     // If the system path maps to a different URL alias, highlight this table
     // row to let the user know of old aliases.
-    if ($data->alias != Drupal::service('path.alias_manager')->getPathAlias($data->source, $data->langcode)) {
+    if ($data->alias != \Drupal::service('path.alias_manager')->getPathAlias($data->source, $data->langcode)) {
       $row['class'] = array('warning');
     }
 
@@ -204,7 +204,7 @@ function path_admin_form($form, &$form_state, $path = array('source' => '', 'ali
  */
 function path_admin_form_delete_submit($form, &$form_state) {
   $destination = array();
-  $query = Drupal::request()->query;
+  $query = \Drupal::request()->query;
   if ($query->has('destination')) {
     $destination = drupal_get_destination();
     $query->remove('destination');
@@ -220,7 +220,7 @@ function path_admin_form_delete_submit($form, &$form_state) {
  */
 function path_admin_form_validate($form, &$form_state) {
   $source = &$form_state['values']['source'];
-  $source = Drupal::service('path.alias_manager')->getSystemPath($source);
+  $source = \Drupal::service('path.alias_manager')->getSystemPath($source);
   $alias = $form_state['values']['alias'];
   $pid = isset($form_state['values']['pid']) ? $form_state['values']['pid'] : 0;
   // Language is only set if language.module is enabled, otherwise save for all
@@ -254,13 +254,13 @@ function path_admin_form_submit($form, &$form_state) {
 
   $pid = isset($form_state['values']['pid']) ? $form_state['values']['pid'] : 0;
   $source = &$form_state['values']['source'];
-  $source = Drupal::service('path.alias_manager')->getSystemPath($source);
+  $source = \Drupal::service('path.alias_manager')->getSystemPath($source);
   $alias = $form_state['values']['alias'];
   // Language is only set if language.module is enabled, otherwise save for all
   // languages.
   $langcode = isset($form_state['values']['langcode']) ? $form_state['values']['langcode'] : Language::LANGCODE_NOT_SPECIFIED;
 
-  Drupal::service('path.crud')->save($source, $alias, $langcode, $pid);
+  \Drupal::service('path.crud')->save($source, $alias, $langcode, $pid);
 
   drupal_set_message(t('The alias has been saved.'));
   $form_state['redirect'] = 'admin/config/search/path';
diff --git a/core/modules/path/path.module b/core/modules/path/path.module
index aeec09181524503271c8b2ba05853a90f1687a25..f7e3084b5bb7e602c3bc0905a120db6ffd9fd48c 100644
--- a/core/modules/path/path.module
+++ b/core/modules/path/path.module
@@ -102,7 +102,7 @@ function path_form_node_form_alter(&$form, $form_state) {
     if ($node->language()->id != Language::LANGCODE_NOT_SPECIFIED) {
       $conditions['langcode'] = $node->language()->id;
     }
-    $path = Drupal::service('path.crud')->load($conditions);
+    $path = \Drupal::service('path.crud')->load($conditions);
     if ($path === FALSE) {
       $path = array();
     }
@@ -114,7 +114,7 @@ function path_form_node_form_alter(&$form, $form_state) {
     'langcode' => $node->language()->id,
   );
 
-  $account = Drupal::currentUser();
+  $account = \Drupal::currentUser();
   $form['path'] = array(
     '#type' => 'details',
     '#title' => t('URL path settings'),
@@ -184,11 +184,11 @@ function path_form_element_validate($element, &$form_state, $complete_form) {
  * Implements hook_form_FORM_ID_alter() for taxonomy_term_form().
  */
 function path_form_taxonomy_term_form_alter(&$form, $form_state) {
-  $account = Drupal::currentUser();
+  $account = \Drupal::currentUser();
   // Make sure this does not show up on the delete confirmation form.
   if (empty($form_state['confirm_delete'])) {
     $term = $form_state['controller']->getEntity();
-    $path = ($term->id() ? Drupal::service('path.crud')->load(array('source' => 'taxonomy/term/' . $term->id())) : array());
+    $path = ($term->id() ? \Drupal::service('path.crud')->load(array('source' => 'taxonomy/term/' . $term->id())) : array());
     if ($path === FALSE) {
       $path = array();
     }
@@ -245,7 +245,7 @@ function path_entity_insert(EntityInterface $entity) {
       // Ensure fields for programmatic executions.
       $uri = $entity->uri();
       $langcode = $entity->language()->id;
-      Drupal::service('path.crud')->save($uri['path'], $entity->path->alias, $langcode);
+      \Drupal::service('path.crud')->save($uri['path'], $entity->path->alias, $langcode);
     }
   }
 }
@@ -258,7 +258,7 @@ function path_entity_update(EntityInterface $entity) {
     $entity->path->alias = trim($entity->path->alias);
     // Delete old alias if user erased it.
     if ($entity->path->pid && !$entity->path->alias) {
-      Drupal::service('path.crud')->delete(array('pid' => $entity->path->pid));
+      \Drupal::service('path.crud')->delete(array('pid' => $entity->path->pid));
     }
     // Only save a non-empty alias.
     if ($entity->path->alias) {
@@ -266,7 +266,7 @@ function path_entity_update(EntityInterface $entity) {
       // Ensure fields for programmatic executions.
       $uri = $entity->uri();
       $langcode = $entity->language()->id;
-      Drupal::service('path.crud')->save($uri['path'], $entity->path->alias, $langcode, $pid);
+      \Drupal::service('path.crud')->save($uri['path'], $entity->path->alias, $langcode, $pid);
     }
   }
 }
@@ -278,7 +278,7 @@ function path_entity_predelete(EntityInterface $entity) {
   if ($entity->getPropertyDefinition('path')) {
     // Delete all aliases associated with this term.
     $uri = $entity->uri();
-    Drupal::service('path.crud')->delete(array('source' => $uri['path']));
+    \Drupal::service('path.crud')->delete(array('source' => $uri['path']));
   }
 }
 
@@ -288,7 +288,7 @@ function path_entity_predelete(EntityInterface $entity) {
 function path_library_info() {
   $libraries['drupal.path'] = array(
     'title' => 'Path',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'path') . '/path.js' => array(),
     ),
diff --git a/core/modules/picture/picture.module b/core/modules/picture/picture.module
index 4926c08e4695b8bcb4dabda18da93b7ccfb17e65..4b527511bf78204e1cc843fb5ad9d6b1c3afb3d4 100644
--- a/core/modules/picture/picture.module
+++ b/core/modules/picture/picture.module
@@ -87,7 +87,7 @@ function picture_library_info() {
   $libraries['picturefill'] = array(
     'title' => t('Picturefill'),
     'website' => 'http://drupal.org/node/1775530',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'picture') . '/picturefill/picturefill.js' => array('type' => 'file', 'weight' => -10, 'group' => JS_DEFAULT),
     ),
diff --git a/core/modules/rdf/rdf.install b/core/modules/rdf/rdf.install
index 117c91053ab80907706ebed8d092e224a4e5df00..bc984f5583f36bf408ce42c96edb90e29a1e98b1 100644
--- a/core/modules/rdf/rdf.install
+++ b/core/modules/rdf/rdf.install
@@ -23,7 +23,7 @@ function rdf_update_8000() {
     $bundle = $row['bundle'];
 
     // Create a config object for the mapping.
-    $config = Drupal::config("rdf.mapping.$entity_type.$bundle")
+    $config = \Drupal::config("rdf.mapping.$entity_type.$bundle")
       ->set('id', "$entity_type.$bundle")
       ->set('uuid', $uuid->generate())
       ->set('targetEntityType', $entity_type)
diff --git a/core/modules/rdf/rdf.module b/core/modules/rdf/rdf.module
index 428f16b250ff3eaf7661dc9ae720ec5dac426886..9708694812a3a96964aa92d64352c70b7c110138 100644
--- a/core/modules/rdf/rdf.module
+++ b/core/modules/rdf/rdf.module
@@ -110,7 +110,7 @@ function rdf_get_namespaces() {
   $namespaces = array();
   // In order to resolve duplicate namespaces by using the earliest defined
   // namespace, do not use \Drupal::moduleHandler()->invokeAll().
-  foreach (Drupal::moduleHandler()->getImplementations('rdf_namespaces') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('rdf_namespaces') as $module) {
     $function = $module . '_rdf_namespaces';
     if (function_exists($function)) {
       $namespaces = NestedArray::mergeDeep($function(), $namespaces);
diff --git a/core/modules/rest/rest.module b/core/modules/rest/rest.module
index a37bfe7aaa91e7d0fa68edb8f0c8e918a57ec4cb..086961af362989841790fcdae437ae563dbdfb73 100644
--- a/core/modules/rest/rest.module
+++ b/core/modules/rest/rest.module
@@ -10,8 +10,8 @@
  */
 function rest_permission() {
   $permissions = array();
-  $manager = Drupal::service('plugin.manager.rest');
-  $resources = Drupal::config('rest.settings')->get('resources');
+  $manager = \Drupal::service('plugin.manager.rest');
+  $resources = \Drupal::config('rest.settings')->get('resources');
   if ($resources && $enabled = array_intersect_key($manager->getDefinitions(), $resources)) {
     foreach ($enabled as $key => $resource) {
       $plugin = $manager->getInstance(array('id' => $key));
diff --git a/core/modules/search/search.module b/core/modules/search/search.module
index a13fd99116805c992e5f2fd4fb67471683a8b822..330e9a7c5d6cbe06f087276ebc7a42d2deb91497 100644
--- a/core/modules/search/search.module
+++ b/core/modules/search/search.module
@@ -179,7 +179,7 @@ function search_menu() {
 
   $default_info = search_get_default_plugin_info();
   if ($default_info) {
-    foreach (Drupal::service('plugin.manager.search')->getActiveDefinitions() as $plugin_id => $search_info) {
+    foreach (\Drupal::service('plugin.manager.search')->getActiveDefinitions() as $plugin_id => $search_info) {
       $path = 'search/' . $search_info['path'];
       $items[$path] = array(
         'title' => $search_info['title'],
@@ -218,8 +218,8 @@ function search_menu() {
  */
 function search_is_active() {
   // This path cannot be accessed if there are no active plugins.
-  $account = Drupal::request()->attributes->get('_account');
-  return !empty($account) && $account->hasPermission('search content') && Drupal::service('plugin.manager.search')->getActiveDefinitions();
+  $account = \Drupal::request()->attributes->get('_account');
+  return !empty($account) && $account->hasPermission('search content') && \Drupal::service('plugin.manager.search')->getActiveDefinitions();
 }
 
 /**
@@ -229,8 +229,8 @@ function search_is_active() {
  *   The search plugin definition for the default search plugin, if any.
  */
 function search_get_default_plugin_info() {
-  $info = Drupal::service('plugin.manager.search')->getActiveDefinitions();
-  $default = Drupal::config('search.settings')->get('default_plugin');
+  $info = \Drupal::service('plugin.manager.search')->getActiveDefinitions();
+  $default = \Drupal::config('search.settings')->get('default_plugin');
   if (isset($info[$default])) {
     return $info[$default];
   }
@@ -251,12 +251,12 @@ function search_get_default_plugin_info() {
  * @see search_menu()
  */
 function _search_menu_access($plugin_id) {
-  $account = Drupal::request()->attributes->get('_account');
+  $account = \Drupal::request()->attributes->get('_account');
   // @todo - remove the empty() check once we are more confident
   // that the account will be populated, especially during tests.
   // @see https://drupal.org/node/2032553
   $access = !empty($account) && $account->hasPermission('search content');
-  return $access && Drupal::service('plugin.manager.search')->pluginAccess($plugin_id, $account);
+  return $access && \Drupal::service('plugin.manager.search')->pluginAccess($plugin_id, $account);
 }
 
 /**
@@ -277,7 +277,7 @@ function _search_menu_access($plugin_id) {
  */
 function search_reindex($sid = NULL, $type = NULL, $reindex = FALSE, $langcode = NULL) {
   if ($type == NULL && $sid == NULL) {
-    foreach (Drupal::service('plugin.manager.search')->getActiveIndexingPlugins() as $plugin) {
+    foreach (\Drupal::service('plugin.manager.search')->getActiveIndexingPlugins() as $plugin) {
       $plugin->resetIndex();
     }
   }
@@ -328,7 +328,7 @@ function search_cron() {
   // to date.
   drupal_register_shutdown_function('search_update_totals');
 
-  foreach (Drupal::service('plugin.manager.search')->getActiveIndexingPlugins() as $plugin) {
+  foreach (\Drupal::service('plugin.manager.search')->getActiveIndexingPlugins() as $plugin) {
     $plugin->updateIndex();
   }
 }
@@ -388,7 +388,7 @@ function search_simplify($text, $langcode = NULL) {
   search_invoke_preprocess($text, $langcode);
 
   // Simple CJK handling
-  if (Drupal::config('search.settings')->get('index.overlap_cjk')) {
+  if (\Drupal::config('search.settings')->get('index.overlap_cjk')) {
     $text = preg_replace_callback('/[' . PREG_CLASS_CJK . ']+/u', 'search_expand_cjk', $text);
   }
 
@@ -442,7 +442,7 @@ function search_simplify($text, $langcode = NULL) {
  *   Tokenized text, starting and ending with a space character.
  */
 function search_expand_cjk($matches) {
-  $min = Drupal::config('search.settings')->get('index.minimum_word_size');
+  $min = \Drupal::config('search.settings')->get('index.minimum_word_size');
   $str = $matches[0];
   $length = drupal_strlen($str);
   // If the text is shorter than the minimum word size, don't tokenize it.
@@ -502,7 +502,7 @@ function _search_index_truncate(&$text) {
  * Invokes hook_search_preprocess() in modules.
  */
 function search_invoke_preprocess(&$text, $langcode = NULL) {
-  foreach (Drupal::moduleHandler()->getImplementations('search_preprocess') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('search_preprocess') as $module) {
     $text = module_invoke($module, 'search_preprocess', $text, $langcode);
   }
 }
@@ -522,12 +522,12 @@ function search_invoke_preprocess(&$text, $langcode = NULL) {
  * @ingroup search
  */
 function search_index($sid, $type, $text, $langcode) {
-  $minimum_word_size = Drupal::config('search.settings')->get('index.minimum_word_size');
+  $minimum_word_size = \Drupal::config('search.settings')->get('index.minimum_word_size');
 
   // Multipliers for scores of words inside certain HTML tags. The weights are
   // stored in config so that modules can overwrite the default weights.
   // Note: 'a' must be included for link ranking to work.
-  $tags = Drupal::config('search.settings')->get('index.tag_weights');
+  $tags = \Drupal::config('search.settings')->get('index.tag_weights');
 
   // Strip off all ignored tags to speed up processing, but insert space before
   // and after them to keep word boundaries.
diff --git a/core/modules/search/search.pages.inc b/core/modules/search/search.pages.inc
index 804e4be34a9b74325fb3a094dbe49a98be270d94..b9e06ab4c91b33028762585826a986b7f61ad9e6 100644
--- a/core/modules/search/search.pages.inc
+++ b/core/modules/search/search.pages.inc
@@ -25,7 +25,7 @@ function search_view($plugin_id = NULL, $keys = '') {
     $keys = trim($_REQUEST['keys']);
   }
 
-  $manager = Drupal::service('plugin.manager.search');
+  $manager = \Drupal::service('plugin.manager.search');
   if (!empty($plugin_id)) {
     $active_plugin_info = $manager->getActiveDefinitions();
     if (isset($active_plugin_info[$plugin_id])) {
@@ -46,7 +46,7 @@ function search_view($plugin_id = NULL, $keys = '') {
     return new RedirectResponse(url($path, array('absolute' => TRUE)));
   }
   $plugin = $manager->createInstance($plugin_id);
-  $request = Drupal::request();
+  $request = \Drupal::request();
   $plugin->setSearch($keys, $request->query->all(), $request->attributes->all());
   // Default results output is an empty string.
   $results = array('#markup' => '');
diff --git a/core/modules/search/tests/modules/search_embedded_form/search_embedded_form.module b/core/modules/search/tests/modules/search_embedded_form/search_embedded_form.module
index d59f184de56b896ea6f21aece6e347cbcc8a6176..680322a0c9a4f34a269c3b1eaaae3d0e24c319f5 100644
--- a/core/modules/search/tests/modules/search_embedded_form/search_embedded_form.module
+++ b/core/modules/search/tests/modules/search_embedded_form/search_embedded_form.module
@@ -30,7 +30,7 @@ function search_embedded_form_menu() {
  * @see search_embedded_form_form_submit().
  */
 function search_embedded_form_form($form, &$form_state) {
-  $count = Drupal::config('search_embedded_form.settings')->get('submitted');
+  $count = \Drupal::config('search_embedded_form.settings')->get('submitted');
 
   $form['name'] = array(
     '#type' => 'textfield',
@@ -56,7 +56,7 @@ function search_embedded_form_form($form, &$form_state) {
  * Submit handler for search_embedded_form_form().
  */
 function search_embedded_form_form_submit($form, &$form_state) {
-  $config = Drupal::config('search_embedded_form.settings');
+  $config = \Drupal::config('search_embedded_form.settings');
   $submit_count = (int) $config->get('submitted');
   $config->set('submitted', $submit_count + 1)->save();
   drupal_set_message(t('Test form was submitted'));
diff --git a/core/modules/shortcut/shortcut.admin.inc b/core/modules/shortcut/shortcut.admin.inc
index c230fb5b11d158beded393eed6a79859a7ac675f..523fead2a3d06eca96ae225f2001648def5cf011 100644
--- a/core/modules/shortcut/shortcut.admin.inc
+++ b/core/modules/shortcut/shortcut.admin.inc
@@ -27,7 +27,7 @@
  * @see shortcut_set_switch_submit()
  */
 function shortcut_set_switch($form, &$form_state, $account = NULL) {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
 
   if (!isset($account)) {
     $account = $user;
@@ -244,7 +244,7 @@ function _shortcut_link_form_elements($shortcut_link = NULL) {
     ));
   }
   else {
-    $shortcut_link['link_path'] = ($shortcut_link['link_path'] == '<front>') ? '' : Drupal::service('path.alias_manager')->getPathAlias($shortcut_link['link_path']);
+    $shortcut_link['link_path'] = ($shortcut_link['link_path'] == '<front>') ? '' : \Drupal::service('path.alias_manager')->getPathAlias($shortcut_link['link_path']);
   }
 
   $form['shortcut_link']['#tree'] = TRUE;
@@ -291,7 +291,7 @@ function shortcut_link_edit_validate($form, &$form_state) {
  */
 function shortcut_link_edit_submit($form, &$form_state) {
   // Normalize the path in case it is an alias.
-  $shortcut_path = Drupal::service('path.alias_manager')->getSystemPath($form_state['values']['shortcut_link']['link_path']);
+  $shortcut_path = \Drupal::service('path.alias_manager')->getSystemPath($form_state['values']['shortcut_link']['link_path']);
   if (empty($shortcut_path)) {
     $shortcut_path = '<front>';
   }
@@ -335,7 +335,7 @@ function shortcut_link_add_submit($form, &$form_state) {
  */
 function shortcut_admin_add_link($shortcut_link, &$shortcut_set) {
   // Normalize the path in case it is an alias.
-  $shortcut_link['link_path'] = Drupal::service('path.alias_manager')->getSystemPath($shortcut_link['link_path']);
+  $shortcut_link['link_path'] = \Drupal::service('path.alias_manager')->getSystemPath($shortcut_link['link_path']);
   if (empty($shortcut_link['link_path'])) {
     $shortcut_link['link_path'] = '<front>';
   }
diff --git a/core/modules/shortcut/shortcut.api.php b/core/modules/shortcut/shortcut.api.php
index 27eecf3d9135ce81996a4f0408c5dcfe896f89f5..fa93e966e5120230d6f16bb7efd86fc21f4fd6e5 100644
--- a/core/modules/shortcut/shortcut.api.php
+++ b/core/modules/shortcut/shortcut.api.php
@@ -32,7 +32,7 @@
  */
 function hook_shortcut_default_set($account) {
   // Use a special set of default shortcuts for administrators only.
-  if (in_array(Drupal::config('user.settings')->get('admin_role'), $account->getRoles())) {
+  if (in_array(\Drupal::config('user.settings')->get('admin_role'), $account->getRoles())) {
     return 'admin-shortcuts';
   }
 }
diff --git a/core/modules/shortcut/shortcut.install b/core/modules/shortcut/shortcut.install
index 76e70973f47ab71d80ca58e5a1c40e425dd97077..6c098a32935a3bef234ed17829dd8331909cea3b 100644
--- a/core/modules/shortcut/shortcut.install
+++ b/core/modules/shortcut/shortcut.install
@@ -84,7 +84,7 @@ function shortcut_update_8000() {
         ->condition('menu_name', 'shortcut-set-1')
         ->execute();
     }
-    Drupal::config('shortcut.set.' . $set->set_name)
+    \Drupal::config('shortcut.set.' . $set->set_name)
       ->set('id', $set->set_name)
       ->set('label', $set->title)
       ->set('uuid', $uuid->generate())
diff --git a/core/modules/shortcut/shortcut.module b/core/modules/shortcut/shortcut.module
index 27f11d7cae3d853916baf320c118cf8c311843f0..e47b5ed02fe191c3519ec0503890681c1afc853a 100644
--- a/core/modules/shortcut/shortcut.module
+++ b/core/modules/shortcut/shortcut.module
@@ -12,7 +12,7 @@
  * Implements hook_help().
  */
 function shortcut_help($path, $arg) {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
 
   switch ($path) {
     case 'admin/help#shortcut':
@@ -171,7 +171,7 @@ function shortcut_admin_paths() {
  *   otherwise.
  */
 function shortcut_set_edit_access($shortcut_set = NULL) {
-  $account = Drupal::currentUser();
+  $account = \Drupal::currentUser();
   // Sufficiently-privileged users can edit their currently displayed shortcut
   // set, but not other sets. Shortcut administrators can edit any set.
   if ($account->hasPermission('administer shortcuts')) {
@@ -196,7 +196,7 @@ function shortcut_set_edit_access($shortcut_set = NULL) {
  *   provided account, FALSE otherwise.
  */
 function shortcut_set_switch_access($account = NULL) {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
 
   if ($user->hasPermission('administer shortcuts')) {
     // Administrators can switch anyone's shortcut set.
@@ -286,7 +286,7 @@ function shortcut_set_reset_link_weights(&$shortcut_set) {
  *   A user account that will be assigned to use the set.
  */
 function shortcut_set_assign_user($shortcut_set, $account) {
-  Drupal::entityManager()
+  \Drupal::entityManager()
     ->getStorageController('shortcut_set')
     ->assignUser($shortcut_set, $account);
 }
@@ -305,7 +305,7 @@ function shortcut_set_assign_user($shortcut_set, $account) {
  *   to any set.
  */
 function shortcut_set_unassign_user($account) {
-  return (bool) Drupal::entityManager()
+  return (bool) \Drupal::entityManager()
     ->getStorageController('shortcut_set')
     ->unassignUser($account);
 }
@@ -334,7 +334,7 @@ function shortcut_current_displayed_set($account = NULL) {
   }
   // If none was found, try to find a shortcut set that is explicitly assigned
   // to this user.
-  $shortcut_set_name = Drupal::entityManager()
+  $shortcut_set_name = \Drupal::entityManager()
     ->getStorageController('shortcut_set')
     ->getAssignedToUser($account);
   if ($shortcut_set_name) {
@@ -370,7 +370,7 @@ function shortcut_default_set($account = NULL) {
   // have one, we allow the last module which returns a valid result to take
   // precedence. If no module returns a valid set, fall back on the site-wide
   // default, which is the lowest-numbered shortcut set.
-  $suggestions = array_reverse(Drupal::moduleHandler()->invokeAll('shortcut_default_set', array($account)));
+  $suggestions = array_reverse(\Drupal::moduleHandler()->invokeAll('shortcut_default_set', array($account)));
   $suggestions[] = 'default';
   foreach ($suggestions as $name) {
     if ($shortcut_set = shortcut_set_load($name)) {
@@ -414,13 +414,13 @@ function shortcut_set_title_exists($title) {
  */
 function shortcut_valid_link($path) {
   // Do not use URL aliases.
-  $normal_path = Drupal::service('path.alias_manager')->getSystemPath($path);
+  $normal_path = \Drupal::service('path.alias_manager')->getSystemPath($path);
   if ($path != $normal_path) {
     $path = $normal_path;
   }
 
   // An empty path is valid too and will be converted to <front>.
-  return (!url_is_external($path) && (Drupal::service('router.route_provider')->getRoutesByPattern('/' . $path)->count() > 0 || menu_get_item($path))) || empty($path) || $path == '<front>';
+  return (!url_is_external($path) && (\Drupal::service('router.route_provider')->getRoutesByPattern('/' . $path)->count() > 0 || menu_get_item($path))) || empty($path) || $path == '<front>';
 }
 
 /**
@@ -564,7 +564,7 @@ function shortcut_library_info() {
   $path = drupal_get_path('module', 'shortcut');
   $libraries['drupal.shortcut.admin'] = array(
     'title' => 'Shortcut configuration',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/shortcut.admin.js' => array(),
     ),
@@ -575,7 +575,7 @@ function shortcut_library_info() {
   );
   $libraries['drupal.shortcut'] = array(
     'title' => 'Shortcut UI',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'css' => array(
       $path . '/css/shortcut.module.css' => array(),
       $path . '/css/shortcut.theme.css' => array(),
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index c0a9102c99326089b174ffc7c1cc6c1a0dac8d27..a8d47099e215e80044b1fce30adeac8e4c1e831e 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -991,7 +991,7 @@ protected function prepareConfigDirectories() {
   }
 
   /**
-   * Rebuild Drupal::getContainer().
+   * Rebuild \Drupal::getContainer().
    *
    * Use this to build a new kernel and service container. For example, when the
    * list of enabled modules is changed via the internal browser, in which case
@@ -1002,14 +1002,14 @@ protected function prepareConfigDirectories() {
    * @see TestBase::tearDown()
    *
    * @todo Fix http://drupal.org/node/1708692 so that module enable/disable
-   *   changes are immediately reflected in Drupal::getContainer(). Until then,
+   *   changes are immediately reflected in \Drupal::getContainer(). Until then,
    *   tests can invoke this workaround when requiring services from newly
    *   enabled modules to be immediately available in the same request.
    */
   protected function rebuildContainer() {
     $this->kernel = new DrupalKernel('testing', drupal_classloader(), FALSE);
     $this->kernel->boot();
-    // DrupalKernel replaces the container in Drupal::getContainer() with a
+    // DrupalKernel replaces the container in \Drupal::getContainer() with a
     // different object, so we need to replace the instance on this test class.
     $this->container = \Drupal::getContainer();
     // The global $user is set in TestBase::prepareEnvironment().
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php b/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
index 505ff333ea5ed4dc9f1d54305b07db55a4afdd55..318e47cb1879bac9271f042d680511b5cef64022 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
@@ -57,7 +57,7 @@ function testEnableModulesLoad() {
     $list = array_keys(\Drupal::moduleHandler()->getModuleList());
     $this->assertFalse(in_array($module, $list), "$module module not found in the extension handler's module list.");
     $list = \Drupal::moduleHandler()->getImplementations('permission');
-    $this->assertFalse(in_array($module, $list), "{$module}_permission() in Drupal::moduleHandler()->getImplementations() not found.");
+    $this->assertFalse(in_array($module, $list), "{$module}_permission() in \Drupal::moduleHandler()->getImplementations() not found.");
 
     // Enable the module.
     $this->enableModules(array($module));
@@ -67,7 +67,7 @@ function testEnableModulesLoad() {
     $list = array_keys(\Drupal::moduleHandler()->getModuleList());
     $this->assertTrue(in_array($module, $list), "$module module found in the extension handler's module list.");
     $list = \Drupal::moduleHandler()->getImplementations('permission');
-    $this->assertTrue(in_array($module, $list), "{$module}_permission() in Drupal::moduleHandler()->getImplementations() found.");
+    $this->assertTrue(in_array($module, $list), "{$module}_permission() in \Drupal::moduleHandler()->getImplementations() found.");
   }
 
   /**
@@ -82,7 +82,7 @@ function testEnableModulesInstall() {
     $list = array_keys(\Drupal::moduleHandler()->getModuleList());
     $this->assertFalse(in_array($module, $list), "$module module not found in the extension handler's module list.");
     $list = \Drupal::moduleHandler()->getImplementations('permission');
-    $this->assertFalse(in_array($module, $list), "{$module}_permission() in Drupal::moduleHandler()->getImplementations() not found.");
+    $this->assertFalse(in_array($module, $list), "{$module}_permission() in \Drupal::moduleHandler()->getImplementations() not found.");
 
     $this->assertFalse(db_table_exists($table), "'$table' database table not found.");
     $schema = drupal_get_schema($table);
@@ -96,7 +96,7 @@ function testEnableModulesInstall() {
     $list = array_keys(\Drupal::moduleHandler()->getModuleList());
     $this->assertTrue(in_array($module, $list), "$module module found in the extension handler's module list.");
     $list = \Drupal::moduleHandler()->getImplementations('permission');
-    $this->assertTrue(in_array($module, $list), "{$module}_permission() in Drupal::moduleHandler()->getImplementations() found.");
+    $this->assertTrue(in_array($module, $list), "{$module}_permission() in \Drupal::moduleHandler()->getImplementations() found.");
 
     $this->assertTrue(db_table_exists($table), "'$table' database table found.");
     $schema = drupal_get_schema($table);
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
index dd725ed802601fc7332e6c8f5c140088a07c84be..350fa5199b07507734c7dc8fe03f666c2d82638d 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
@@ -15,7 +15,7 @@
  *
  * These tests can not access the database nor files. Calling any Drupal
  * function that needs the database will throw exceptions. These include
- * watchdog(), Drupal::moduleHandler()->getImplementations(), module_invoke_all() etc.
+ * watchdog(), \Drupal::moduleHandler()->getImplementations(), module_invoke_all() etc.
  */
 abstract class UnitTestBase extends TestBase {
 
diff --git a/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
index 2dcb725b1101e58442484a091b3f3960d86e258a..d04012eb408372b72d3598f41d31281a5e5f58f3 100644
--- a/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -159,7 +159,7 @@ function simpletest_run_tests($test_list, $reporter = 'drupal') {
   );
   batch_set($batch);
 
-  Drupal::moduleHandler()->invokeAll('test_group_started');
+  \Drupal::moduleHandler()->invokeAll('test_group_started');
 
   return $test_id;
 }
@@ -305,7 +305,7 @@ function _simpletest_batch_operation($test_list_init, $test_id, &$context) {
   $size = count($test_list);
   $info = $test->getInfo();
 
-  Drupal::moduleHandler()->invokeAll('test_finished', array($test->results));
+  \Drupal::moduleHandler()->invokeAll('test_finished', array($test->results));
 
   // Gather results and compose the report.
   $test_results[$test_class] = $test->results;
@@ -352,7 +352,7 @@ function _simpletest_batch_finished($success, $results, $operations, $elapsed) {
     drupal_set_message(t('The test run did not successfully finish.'), 'error');
     drupal_set_message(t('Use the <em>Clean environment</em> button to clean-up temporary files and tables.'), 'warning');
   }
-  Drupal::moduleHandler()->invokeAll('test_group_finished');
+  \Drupal::moduleHandler()->invokeAll('test_group_finished');
 }
 
 /**
@@ -573,7 +573,7 @@ function simpletest_generate_file($filename, $width, $lines, $type = 'binary-tex
 function simpletest_clean_environment() {
   simpletest_clean_database();
   simpletest_clean_temporary_directories();
-  if (Drupal::config('simpletest.settings')->get('clear_results')) {
+  if (\Drupal::config('simpletest.settings')->get('clear_results')) {
     $count = simpletest_clean_results_table();
     drupal_set_message(format_plural($count, 'Removed 1 test result.', 'Removed @count test results.'));
   }
@@ -643,7 +643,7 @@ function simpletest_clean_temporary_directories() {
  *   The number of results removed.
  */
 function simpletest_clean_results_table($test_id = NULL) {
-  if (Drupal::config('simpletest.settings')->get('clear_results')) {
+  if (\Drupal::config('simpletest.settings')->get('clear_results')) {
     if ($test_id) {
       $count = db_query('SELECT COUNT(test_id) FROM {simpletest_test_id} WHERE test_id = :test_id', array(':test_id' => $test_id))->fetchField();
 
@@ -686,7 +686,7 @@ function simpletest_mail_alter(&$message) {
 function simpletest_library_info() {
   $libraries['drupal.simpletest'] = array(
     'title' => 'Simpletest',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'simpletest') . '/simpletest.js' => array(),
     ),
diff --git a/core/modules/statistics/statistics.install b/core/modules/statistics/statistics.install
index 5706db32fe56b4446ab0361c9eab817c6aa318e1..9b443e5f7aa000d4aadfb5005189754b7776102f 100644
--- a/core/modules/statistics/statistics.install
+++ b/core/modules/statistics/statistics.install
@@ -10,8 +10,8 @@
  */
 function statistics_uninstall() {
   // Remove states.
-  Drupal::state()->delete('statistics.node_counter_scale');
-  Drupal::state()->delete('statistics.day_timestamp');
+  \Drupal::state()->delete('statistics.node_counter_scale');
+  \Drupal::state()->delete('statistics.day_timestamp');
 }
 
 /**
diff --git a/core/modules/statistics/statistics.module b/core/modules/statistics/statistics.module
index 8ef3136fb80c948892398a9002080e6bdb8db081..34fd8d3a7dd587b36850a7790e790446c8c272f4 100644
--- a/core/modules/statistics/statistics.module
+++ b/core/modules/statistics/statistics.module
@@ -90,14 +90,14 @@ function statistics_menu() {
  * Implements hook_cron().
  */
 function statistics_cron() {
-  $statistics_timestamp = Drupal::state()->get('statistics.day_timestamp') ?: 0;
+  $statistics_timestamp = \Drupal::state()->get('statistics.day_timestamp') ?: 0;
 
   if ((REQUEST_TIME - $statistics_timestamp) >= 86400) {
     // Reset day counts.
     db_update('node_counter')
       ->fields(array('daycount' => 0))
       ->execute();
-    Drupal::state()->set('statistics.day_timestamp', REQUEST_TIME);
+    \Drupal::state()->set('statistics.day_timestamp', REQUEST_TIME);
   }
 }
 
@@ -174,7 +174,7 @@ function statistics_get($nid) {
  *   A string as a link, truncated to the width, linked to the given $path.
  */
 function _statistics_link($path, $width = 35) {
-  $title = Drupal::service('path.alias_manager')->getPathAlias($path);
+  $title = \Drupal::service('path.alias_manager')->getPathAlias($path);
   $title = truncate_utf8($title, $width, FALSE, TRUE);
   return l($title, $path);
 }
@@ -211,7 +211,7 @@ function statistics_node_predelete(EntityInterface $node) {
  * Implements hook_ranking().
  */
 function statistics_ranking() {
-  if (Drupal::config('statistics.settings')->get('count_content_views')) {
+  if (\Drupal::config('statistics.settings')->get('count_content_views')) {
     return array(
       'views' => array(
         'title' => t('Number of views'),
@@ -223,7 +223,7 @@ function statistics_ranking() {
         ),
         // Inverse law that maps the highest view count on the site to 1 and 0 to 0.
         'score' => '2.0 - 2.0 / (1.0 + node_counter.totalcount * CAST(:scale AS DECIMAL))',
-        'arguments' => array(':scale' => Drupal::state()->get('statistics.node_counter_scale') ?: 0),
+        'arguments' => array(':scale' => \Drupal::state()->get('statistics.node_counter_scale') ?: 0),
       ),
     );
   }
@@ -233,7 +233,7 @@ function statistics_ranking() {
  * Implements hook_update_index().
  */
 function statistics_update_index() {
-  Drupal::state()->set('statistics.node_counter_scale', 1.0 / max(1, db_query('SELECT MAX(totalcount) FROM {node_counter}')->fetchField()));
+  \Drupal::state()->set('statistics.node_counter_scale', 1.0 / max(1, db_query('SELECT MAX(totalcount) FROM {node_counter}')->fetchField()));
 }
 
 /**
@@ -251,7 +251,7 @@ function statistics_preprocess_block(&$variables) {
 function statistics_library_info() {
   $libraries['drupal.statistics'] = array(
     'title' => 'Statistics',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'statistics') . '/statistics.js' => array(
         'scope' => 'footer'
@@ -274,7 +274,7 @@ function statistics_library_info() {
  * to count content views.
  */
 function statistics_block_alter(&$definitions) {
-  $statistics_count_content_views = Drupal::config('statistics.settings')->get('count_content_views');
+  $statistics_count_content_views = \Drupal::config('statistics.settings')->get('count_content_views');
   if (empty($statistics_count_content_views)) {
     unset($definitions['statistics_popular_block']);
   }
diff --git a/core/modules/statistics/statistics.tokens.inc b/core/modules/statistics/statistics.tokens.inc
index 02de3a09b74d366085e9d41256e9b52917808cd5..d2be86c20bb0c24c174349235ec805a0cf45e0a1 100644
--- a/core/modules/statistics/statistics.tokens.inc
+++ b/core/modules/statistics/statistics.tokens.inc
@@ -32,7 +32,7 @@ function statistics_token_info() {
  * Implements hook_tokens().
  */
 function statistics_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $replacements = array();
 
diff --git a/core/modules/syslog/syslog.install b/core/modules/syslog/syslog.install
index c9eb769350e4d04043a36681f6ad34a4b25aef03..c36feeb8fa4d0d63e0b61a8c99036ae2ff90e29f 100644
--- a/core/modules/syslog/syslog.install
+++ b/core/modules/syslog/syslog.install
@@ -11,7 +11,7 @@
 function syslog_install() {
   // The default facility setting depends on the operating system, so it needs
   // to be set dynamically during installation.
-  Drupal::config('syslog.settings')->set('facility', defined('LOG_LOCAL0') ? LOG_LOCAL0 : LOG_USER)->save();
+  \Drupal::config('syslog.settings')->set('facility', defined('LOG_LOCAL0') ? LOG_LOCAL0 : LOG_USER)->save();
 }
 
 /**
diff --git a/core/modules/syslog/syslog.module b/core/modules/syslog/syslog.module
index c46f58aec0636a94d250148626064d20b81882fa..51c5792ae5c9866724ce4e01528167c4c6e805d3 100644
--- a/core/modules/syslog/syslog.module
+++ b/core/modules/syslog/syslog.module
@@ -45,7 +45,7 @@ function syslog_help($path, $arg) {
  * Implements hook_form_FORM_ID_alter().
  */
 function syslog_form_system_logging_settings_alter(&$form, &$form_state) {
-  $config = Drupal::config('syslog.settings');
+  $config = \Drupal::config('syslog.settings');
   $help = module_exists('help') ? ' ' . l(t('More information'), 'admin/help/syslog') . '.' : NULL;
   $form['syslog_identity'] = array(
     '#type'          => 'textfield',
@@ -78,7 +78,7 @@ function syslog_form_system_logging_settings_alter(&$form, &$form_state) {
  * @see syslog_form_system_logging_settings_alter()
  */
 function syslog_logging_settings_submit($form, &$form_state) {
-  Drupal::config('syslog.settings')
+  \Drupal::config('syslog.settings')
     ->set('identity', $form_state['values']['syslog_identity'])
     ->set('facility', $form_state['values']['syslog_facility'])
     ->set('format', $form_state['values']['syslog_format'])
@@ -111,7 +111,7 @@ function syslog_watchdog(array $log_entry) {
   global $base_url;
 
   $log_init = &drupal_static(__FUNCTION__, FALSE);
-  $config = Drupal::config('syslog.settings');
+  $config = \Drupal::config('syslog.settings');
 
   if (!$log_init) {
     $log_init = TRUE;
diff --git a/core/modules/system/language.api.php b/core/modules/system/language.api.php
index 2e8d91f10203d3c46b344ad26796a06b984e534d..cfa42ec5b96e923bd8b2797ca639585df791e493 100644
--- a/core/modules/system/language.api.php
+++ b/core/modules/system/language.api.php
@@ -199,7 +199,7 @@ function hook_language_fallback_candidates_alter(array &$fallback_candidates) {
  * // Use the current default interface language.
  * $langcode = language(\Drupal\Core\Language\Language::TYPE_INTERFACE)->id;
  * // Instantiate the transliteration class.
- * $trans = Drupal::transliteration();
+ * $trans = \Drupal::transliteration();
  * // Use this to transliterate some text.
  * $transformed = $trans->transliterate($string, $langcode);
  * @endcode
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
index 4f650bf80e9d2ad36dbb8f8630b8a919f088ee35..3487fd4b700744cd23c3ee3b0ec5c9c42eeee6db 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
@@ -14,7 +14,7 @@
 /**
  * Tests for URL generation functions.
  *
- * url() calls Drupal::moduleHandler()->getImplementations(),
+ * url() calls \Drupal::moduleHandler()->getImplementations(),
  * which may issue a db query, which requires
  * inheriting from a web test case rather than a unit test case.
  */
diff --git a/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php b/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php
index 8ca5379bc90089de07153d3b416a84b0302151de..d6362b5f568347df917375bd267a97b93466e2ca 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php
@@ -81,7 +81,7 @@ protected function assertModuleList(Array $expected_values, $condition) {
   }
 
   /**
-   * Test Drupal::moduleHandler()->getImplementations() caching.
+   * Test \Drupal::moduleHandler()->getImplementations() caching.
    */
   function testModuleImplements() {
     // Clear the cache.
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index cefffd1244da230049d4f4016b35e2e55bcc54cc..5f6d62f7a28ac5d2a4cbe8bdb85f1165b9f93eda 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -18,9 +18,9 @@ function system_themes_page() {
   $themes = system_rebuild_theme_data();
   uasort($themes, 'system_sort_modules_by_info_name');
 
-  $theme_default = Drupal::config('system.theme')->get('default');
+  $theme_default = \Drupal::config('system.theme')->get('default');
   $theme_groups  = array();
-  $admin_theme = Drupal::config('system.theme')->get('admin');
+  $admin_theme = \Drupal::config('system.theme')->get('admin');
 
   foreach ($themes as &$theme) {
     if (!empty($theme->info['hidden'])) {
@@ -55,7 +55,7 @@ function system_themes_page() {
      // Ensure this theme is compatible with this version of core.
      // Require the 'content' region to make sure the main page
      // content has a common place in all themes.
-      $theme->incompatible_core = !isset($theme->info['core']) || ($theme->info['core'] != Drupal::CORE_COMPATIBILITY) || (!isset($theme->info['regions']['content']));
+      $theme->incompatible_core = !isset($theme->info['core']) || ($theme->info['core'] != \Drupal::CORE_COMPATIBILITY) || (!isset($theme->info['regions']['content']));
       $theme->incompatible_php = version_compare(phpversion(), $theme->info['php']) < 0;
       // Confirmed that the base theme is available.
       $theme->incompatible_base = (isset($theme->info['base theme']) && !isset($themes[$theme->info['base theme']]));
@@ -157,7 +157,7 @@ function system_themes_admin_form($form, &$form_state, $theme_options) {
     '#options' => array(0 => t('Default theme')) + $theme_options,
     '#title' => t('Administration theme'),
     '#description' => t('Choose "Default theme" to always use the same theme as the rest of the site.'),
-    '#default_value' => Drupal::config('system.theme')->get('admin'),
+    '#default_value' => \Drupal::config('system.theme')->get('admin'),
   );
   $form['admin_theme']['actions'] = array('#type' => 'actions');
   $form['admin_theme']['actions']['submit'] = array(
@@ -172,14 +172,14 @@ function system_themes_admin_form($form, &$form_state, $theme_options) {
  */
 function system_themes_admin_form_submit($form, &$form_state) {
   drupal_set_message(t('The configuration options have been saved.'));
-  Drupal::config('system.theme')->set('admin', $form_state['values']['admin_theme'])->save();
+  \Drupal::config('system.theme')->set('admin', $form_state['values']['admin_theme'])->save();
 }
 
 /**
  * Menu callback; Set the default theme.
  */
 function system_theme_default() {
-  $request = Drupal::request();
+  $request = \Drupal::request();
   $theme = $request->get('theme');
   $token = $request->get('token');
   if (!empty($theme) && !empty($token) && drupal_valid_token($token, 'system-theme-operation-link')) {
@@ -193,7 +193,7 @@ function system_theme_default() {
        theme_enable(array($theme));
       }
       // Set the default theme.
-      Drupal::config('system.theme')
+      \Drupal::config('system.theme')
         ->set('default', $theme)
         ->save();
 
@@ -207,7 +207,7 @@ function system_theme_default() {
 
       // The status message depends on whether an admin theme is currently in use:
       // a value of 0 means the admin theme is set to be the default theme.
-      $admin_theme = Drupal::config('system.theme')->get('admin');
+      $admin_theme = \Drupal::config('system.theme')->get('admin');
       if ($admin_theme != 0 && $admin_theme != $theme) {
         drupal_set_message(t('Please note that the administration theme is still set to the %admin_theme theme; consequently, the theme on this page remains unchanged. All non-administrative sections of the site, however, will show the selected %selected_theme theme by default.', array(
           '%admin_theme' => $themes[$admin_theme]->info['name'],
@@ -691,7 +691,7 @@ function theme_system_themes_page($variables) {
 
       // Make sure to provide feedback on compatibility.
       if (!empty($theme->incompatible_core)) {
-        $output .= '<div class="incompatible">' . t('This version is not compatible with Drupal !core_version and should be replaced.', array('!core_version' => Drupal::CORE_COMPATIBILITY)) . '</div>';
+        $output .= '<div class="incompatible">' . t('This version is not compatible with Drupal !core_version and should be replaced.', array('!core_version' => \Drupal::CORE_COMPATIBILITY)) . '</div>';
       }
       elseif (!empty($theme->incompatible_php)) {
         if (substr_count($theme->info['php'], '.') < 2) {
@@ -748,8 +748,8 @@ function system_date_format_localize_form($form, &$form_state, $langcode) {
   );
 
   // Get list of available formats.
-  $date_service = Drupal::service('date');
-  $formats = Drupal::entityManager()
+  $date_service = \Drupal::service('date');
+  $formats = \Drupal::entityManager()
     ->getStorageController('date_format')
     ->loadMultiple();
   $choices = array();
@@ -849,7 +849,7 @@ function theme_system_date_format_localize_form($variables) {
  */
 function system_date_format_localize_form_save($langcode, $date_format_id, DateFormatInterface $format) {
   $format->addLocale($langcode)->save();
-  Drupal::config('locale.config.' . $langcode . '.system.date_format.' . $date_format_id)
+  \Drupal::config('locale.config.' . $langcode . '.system.date_format.' . $date_format_id)
     ->set('pattern', $format->get('pattern'))
     ->save();
 }
diff --git a/core/modules/system/system.api.php b/core/modules/system/system.api.php
index d366e018a1130e2eca6d3e60441f5048e4ff1231..78d749d5b0eee5769f6c8f37e0be0dc0f0da6e1e 100644
--- a/core/modules/system/system.api.php
+++ b/core/modules/system/system.api.php
@@ -125,7 +125,7 @@ function hook_cron() {
     ':time' => REQUEST_TIME,
     ':never' => AGGREGATOR_CLEAR_NEVER,
   ));
-  $queue = Drupal::queue('aggregator_feeds');
+  $queue = \Drupal::queue('aggregator_feeds');
   foreach ($result as $feed) {
     $queue->createItem($feed);
   }
@@ -1357,14 +1357,14 @@ function hook_mail_alter(&$message) {
       $message['send'] = FALSE;
       return;
     }
-    $message['body'][] = "--\nMail sent out from " . Drupal::config('system.site')->get('name');
+    $message['body'][] = "--\nMail sent out from " . \Drupal::config('system.site')->get('name');
   }
 }
 
 /**
  * Alter the registry of modules implementing a hook.
  *
- * This hook is invoked during Drupal::moduleHandler()->getImplementations().
+ * This hook is invoked during \Drupal::moduleHandler()->getImplementations().
  * A module may implement this hook in order to reorder the implementing
  * modules, which are otherwise ordered by the module's system weight.
  *
@@ -1387,7 +1387,7 @@ function hook_mail_alter(&$message) {
 function hook_module_implements_alter(&$implementations, $hook) {
   if ($hook == 'rdf_mapping') {
     // Move my_module_rdf_mapping() to the end of the list.
-    // Drupal::moduleHandler()->getImplementations()
+    // \Drupal::moduleHandler()->getImplementations()
     // iterates through $implementations with a foreach loop which PHP iterates
     // in the order that the items were added, so to move an item to the end of
     // the array, we remove it and then add it.
@@ -1717,7 +1717,7 @@ function hook_template_preprocess_default_variables_alter(&$variables) {
  */
 function hook_custom_theme() {
   // Allow the user to request a particular theme via a query parameter.
-  return Drupal::request()->query->get('theme');
+  return \Drupal::request()->query->get('theme');
 }
 
 /**
@@ -1775,7 +1775,7 @@ function hook_watchdog(array $log_entry) {
   $to = 'someone@example.com';
   $params = array();
   $params['subject'] = t('[@site_name] @severity_desc: Alert from your web site', array(
-    '@site_name' => Drupal::config('system.site')->get('name'),
+    '@site_name' => \Drupal::config('system.site')->get('name'),
     '@severity_desc' => $severity_list[$log_entry['severity']],
   ));
 
@@ -1841,7 +1841,7 @@ function hook_mail($key, &$message, $params) {
   $account = $params['account'];
   $context = $params['context'];
   $variables = array(
-    '%site_name' => Drupal::config('system.site')->get('name'),
+    '%site_name' => \Drupal::config('system.site')->get('name'),
     '%username' => user_format_name($account),
   );
   if ($context['hook'] == 'taxonomy') {
@@ -2150,7 +2150,7 @@ function hook_file_download($uri) {
       return -1;
     }
     else {
-      $image = Drupal::service('image.factory')->get($uri);
+      $image = \Drupal::service('image.factory')->get($uri);
       return array('Content-Type' => $image->getMimeType());
     }
   }
@@ -2277,7 +2277,7 @@ function hook_requirements($phase) {
   if ($phase == 'runtime') {
     $requirements['drupal'] = array(
       'title' => t('Drupal'),
-      'value' => Drupal::VERSION,
+      'value' => \Drupal::VERSION,
       'severity' => REQUIREMENT_INFO
     );
   }
@@ -3119,7 +3119,7 @@ function hook_url_outbound_alter(&$path, &$options, $original_path) {
  * @see hook_tokens_alter()
  */
 function hook_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $url_options = array('absolute' => TRUE);
   if (isset($options['langcode'])) {
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index 5222f25b96cc32201bbf95c807784e80495e745a..fba64c9614d39cbee7a657327cb9eb6a80ed0051 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -22,7 +22,7 @@ function system_requirements($phase) {
   if ($phase == 'runtime') {
     $requirements['drupal'] = array(
       'title' => t('Drupal'),
-      'value' => Drupal::VERSION,
+      'value' => \Drupal::VERSION,
       'severity' => REQUIREMENT_INFO,
       'weight' => -10,
     );
@@ -260,7 +260,7 @@ function system_requirements($phase) {
 
   // Report cron status.
   if ($phase == 'runtime') {
-    $cron_config = Drupal::config('system.cron');
+    $cron_config = \Drupal::config('system.cron');
     // Cron warning threshold defaults to two days.
     $threshold_warning = $cron_config->get('threshold.requirements_warning');
     // Cron error threshold defaults to two weeks.
@@ -269,7 +269,7 @@ function system_requirements($phase) {
     $help = t('For more information, see the online handbook entry for <a href="@cron-handbook">configuring cron jobs</a>.', array('@cron-handbook' => 'http://drupal.org/cron'));
 
     // Determine when cron last ran.
-    $cron_last = Drupal::state()->get('system.cron_last');
+    $cron_last = \Drupal::state()->get('system.cron_last');
     if (!is_numeric($cron_last)) {
       $cron_last = variable_get('install_time', 0);
     }
@@ -291,7 +291,7 @@ function system_requirements($phase) {
     }
 
     $description .= ' ' . t('You can <a href="@cron">run cron manually</a>.', array('@cron' => url('admin/reports/status/run-cron')));
-    $description .= '<br />' . t('To run cron from outside the site, go to <a href="!cron">!cron</a>', array('!cron' => url('cron/' . Drupal::state()->get('system.cron_key'), array('absolute' => TRUE))));
+    $description .= '<br />' . t('To run cron from outside the site, go to <a href="!cron">!cron</a>', array('!cron' => url('cron/' . \Drupal::state()->get('system.cron_key'), array('absolute' => TRUE))));
 
     $requirements['cron'] = array(
       'title' => t('Cron maintenance tasks'),
@@ -301,7 +301,7 @@ function system_requirements($phase) {
     );
   }
   if ($phase != 'install') {
-    $filesystem_config = Drupal::config('system.file');
+    $filesystem_config = \Drupal::config('system.file');
     $directories = array(
       PublicStream::basePath(),
       // By default no private files directory is configured. For private files
@@ -413,7 +413,7 @@ function system_requirements($phase) {
     );
 
     // Check installed modules.
-    foreach (Drupal::moduleHandler()->getModuleList() as $module => $filename) {
+    foreach (\Drupal::moduleHandler()->getModuleList() as $module => $filename) {
       $updates = drupal_get_schema_versions($module);
       if ($updates !== FALSE) {
         $default = drupal_get_installed_schema_version($module);
@@ -476,7 +476,7 @@ function system_requirements($phase) {
         // Check for an incompatible version.
         $required_file = $files[$required_module];
         $required_name = $required_file->info['name'];
-        $version = str_replace(Drupal::CORE_COMPATIBILITY . '-', '', $required_file->info['version']);
+        $version = str_replace(\Drupal::CORE_COMPATIBILITY . '-', '', $required_file->info['version']);
         $compatibility = drupal_check_incompatibility($requirement, $version);
         if ($compatibility) {
           $compatibility = rtrim(substr($compatibility, 2), ')');
@@ -523,13 +523,13 @@ function system_install() {
   // Enable and set the default theme. Can't use theme_enable() this early in
   // installation.
   config_install_default_config('theme', 'stark');
-  Drupal::config('system.theme')
+  \Drupal::config('system.theme')
     ->set('default', 'stark')
     ->save();
 
   // Populate the cron key state variable.
   $cron_key = Crypt::randomStringHashed(55);
-  Drupal::state()->set('system.cron_key', $cron_key);
+  \Drupal::state()->set('system.cron_key', $cron_key);
 }
 
 /**
@@ -1427,7 +1427,7 @@ function system_update_8013() {
 function system_update_8014() {
   // Not using update_variables_to_config(), since the only value is
   // 'error_level', which needs to be mapped to a new value.
-  $config = Drupal::config('system.logging');
+  $config = \Drupal::config('system.logging');
   $error_level = db_query("SELECT value FROM {variable} WHERE name = 'error_level'")->fetchField();
   if ($error_level !== FALSE) {
     $error_level = unserialize($error_level);
@@ -1688,7 +1688,7 @@ function system_update_8028() {
  */
 function system_update_8029() {
   if ($value = update_variable_get('path_alias_whitelist', FALSE)) {
-    Drupal::state()->set('system.path_alias_whitelist', $value);
+    \Drupal::state()->set('system.path_alias_whitelist', $value);
   }
   update_variable_del('path_alias_whitelist');
 }
@@ -1884,7 +1884,7 @@ function system_update_8045() {
   if (!empty($date_formats)) {
     foreach ($date_formats as $type => $format) {
       // Set name and locked properties.
-      $config = Drupal::config("system.date_format.$type")
+      $config = \Drupal::config("system.date_format.$type")
         ->set('id', $type)
         ->set('label', $format['title'])
         ->set('locked', $format['locked'])
@@ -1929,7 +1929,7 @@ function system_update_8046() {
   update_install_default_config('module', 'views.view.user_admin_people', 'user');
   update_install_default_config('module', 'views.view.content', 'node');
 
-  $front_page = Drupal::config('system.site')->get('page.front') ?: 'node';
+  $front_page = \Drupal::config('system.site')->get('page.front') ?: 'node';
   if ($front_page == 'node') {
     // This imports the node frontpage view.
     update_install_default_config('module', 'views.view.frontpage', 'node');
@@ -2132,7 +2132,7 @@ function system_update_8055() {
   // Convert array of theme settings from Drupal 7's variable system to Drupal
   // 8's configuration management system.
   foreach ($theme_settings_to_config_map as $variable => $config_name) {
-    $config = Drupal::config($config_name);
+    $config = \Drupal::config($config_name);
     $theme_settings = update_variable_get($variable);
     if (!empty($theme_settings)) {
       theme_settings_convert_to_config($theme_settings, $config)->save();
@@ -2176,7 +2176,7 @@ function system_update_8056() {
   foreach ($entity_view_modes as $entity_type => $view_modes) {
     foreach ($view_modes as $key => $name) {
       $status = in_array($key, array('teaser', 'compact'));
-      Drupal::config("entity.view_mode.$entity_type.$key")
+      \Drupal::config("entity.view_mode.$entity_type.$key")
         ->set('id', "$entity_type.$key")
         ->set('label', $name)
         ->set('targetEntityType', $entity_type)
@@ -2193,14 +2193,14 @@ function system_update_8056() {
  */
 function system_update_8057() {
   $actions = db_query("SELECT * FROM {actions}")->fetchAllAssoc('aid', PDO::FETCH_ASSOC);
-  $action_plugins = Drupal::service('plugin.manager.action')->getDefinitions();
+  $action_plugins = \Drupal::service('plugin.manager.action')->getDefinitions();
   foreach ($actions as $action) {
     if (isset($action_plugins[$action['callback']])) {
       if (is_numeric($action['aid'])) {
         $action['aid'] = $action['callback'] . '_' . $action['aid'];
       }
       $configuration = unserialize($action['parameters']) ?: array();
-      Drupal::config('system.action.' . $action['aid'])
+      \Drupal::config('system.action.' . $action['aid'])
         ->set('id', $action['aid'])
         ->set('label', $action['label'])
         ->set('status', '1')
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index d31cd3c2198b831bab0f51b1ab4b57ef809ca67a..f62f64063a3cede04bbe21e7cec3e03b7af86ab7 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -219,7 +219,7 @@ function system_permission() {
     ),
     'view the administration theme' => array(
       'title' => t('View the administration theme'),
-      'description' => Drupal::config('system.theme')->get('admin') ?: t('This is only used when the site is configured to use a separate administration theme on the <a href="@appearance-url">Appearance</a> page.', array('@appearance-url' => url('admin/appearance'))),
+      'description' => \Drupal::config('system.theme')->get('admin') ?: t('This is only used when the site is configured to use a separate administration theme on the <a href="@appearance-url">Appearance</a> page.', array('@appearance-url' => url('admin/appearance'))),
     ),
     'access site reports' => array(
       'title' => t('View site reports'),
@@ -932,7 +932,7 @@ function _system_batch_theme() {
   // Retrieve the current state of the batch.
   $batch = &batch_get();
   if (!$batch && isset($_REQUEST['id'])) {
-    $batch = Drupal::service('batch.storage')->load($_REQUEST['id']);
+    $batch = \Drupal::service('batch.storage')->load($_REQUEST['id']);
   }
   // Use the same theme as the page that started the batch.
   if (!empty($batch['theme'])) {
@@ -947,7 +947,7 @@ function system_library_info() {
   // Drupal-specific JavaScript.
   $libraries['drupal'] = array(
     'title' => 'Drupal',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/drupal.js' => array('group' => JS_LIBRARY, 'weight' => -18),
     ),
@@ -959,7 +959,7 @@ function system_library_info() {
   // Drupal settings.
   $libraries['drupalSettings'] = array(
     'title' => 'Drupal Settings',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       array('type' => 'setting', 'data' => array()),
     ),
@@ -969,7 +969,7 @@ function system_library_info() {
   $libraries['drupal.ajax'] = array(
     'title' => 'Drupal AJAX',
     'website' => 'http://api.drupal.org/api/group/ajax/8',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/ajax.js' => array('group' => JS_LIBRARY, 'weight' => 2),
     ),
@@ -985,7 +985,7 @@ function system_library_info() {
   // Drupal's Screen Reader change announcement utility.
   $libraries['drupal.announce'] = array(
     'title' => 'Drupal announce',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/announce.js' => array('group' => JS_LIBRARY),
     ),
@@ -998,7 +998,7 @@ function system_library_info() {
   // Drupal's batch API.
   $libraries['drupal.batch'] = array(
     'title' => 'Drupal batch API',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/batch.js' => array('group' => JS_DEFAULT, 'cache' => FALSE),
     ),
@@ -1015,7 +1015,7 @@ function system_library_info() {
   // Drupal's progress indicator.
   $libraries['drupal.progress'] = array(
     'title' => 'Drupal progress indicator',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/progress.js' => array('group' => JS_DEFAULT),
     ),
@@ -1029,7 +1029,7 @@ function system_library_info() {
   // Drupal's form library.
   $libraries['drupal.form'] = array(
     'title' => 'Drupal form library',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/form.js' => array('group' => JS_LIBRARY, 'weight' => 1),
     ),
@@ -1044,7 +1044,7 @@ function system_library_info() {
   // Drupal's dialog component.
   $libraries['drupal.dialog'] = array(
     'title' => 'Drupal Dialog',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/dialog.js' => array('group' => JS_LIBRARY),
     ),
@@ -1063,7 +1063,7 @@ function system_library_info() {
   // Drupal's integration between AJAX and dialogs.
   $libraries['drupal.dialog.ajax'] = array(
     'title' => 'Drupal Dialog AJAX',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/dialog.ajax.js' => array('group' => JS_LIBRARY, 'weight' => 3),
     ),
@@ -1079,7 +1079,7 @@ function system_library_info() {
   // Drupal's states library.
   $libraries['drupal.states'] = array(
     'title' => 'Drupal states',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/states.js' => array('group' => JS_LIBRARY, 'weight' => 1),
     ),
@@ -1094,7 +1094,7 @@ function system_library_info() {
   // Drupal's tabledrag library.
   $libraries['drupal.tabledrag'] = array(
     'title' => 'Drupal tabledrag',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/tabledrag.js' => array('group' => JS_LIBRARY, 'weight' => -1),
     ),
@@ -1111,7 +1111,7 @@ function system_library_info() {
   // Drupal's responsive table API.
   $libraries['drupal.tableresponsive'] = array(
     'title' => 'Drupal responsive table API',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/tableresponsive.js' => array('group' => JS_LIBRARY),
     ),
@@ -1125,7 +1125,7 @@ function system_library_info() {
   // Collapsible details.
   $libraries['drupal.collapse'] = array(
     'title' => 'Collapsible details',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/collapse.js' => array('group' => JS_DEFAULT),
     ),
@@ -1142,7 +1142,7 @@ function system_library_info() {
   // Drupal's autocomplete widget.
   $libraries['drupal.autocomplete'] = array(
     'title' => 'Drupal autocomplete',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/autocomplete.js' => array('group' => JS_DEFAULT),
     ),
@@ -1158,7 +1158,7 @@ function system_library_info() {
   // elements like the overlay.
   $libraries['drupal.displace'] = array(
     'title' => 'Drupal displace',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/displace.js' => array('group' => JS_LIBRARY),
     ),
@@ -1172,7 +1172,7 @@ function system_library_info() {
   // Manages tab orders in the document.
   $libraries['drupal.tabbingmanager'] = array(
     'title' => 'Drupal tabbing manager',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/tabbingmanager.js' => array('group' => JS_LIBRARY),
     ),
@@ -1187,7 +1187,7 @@ function system_library_info() {
   // A utility function to limit calls to a function with a given time.
   $libraries['drupal.debounce'] = array(
     'title' => 'Drupal debounce',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/debounce.js' => array('group' => JS_LIBRARY),
     ),
@@ -1301,7 +1301,7 @@ function system_library_info() {
   $libraries['matchmedia'] = array(
     'title' => 'window.matchMedia polyfill',
     'website' => 'http://drupal.org/node/1815602',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/matchmedia.js' => array(),
     ),
@@ -1372,7 +1372,7 @@ function system_library_info() {
   // Drupal's base CSS.
   $libraries['drupal.base'] = array(
     'title' => 'Drupal base CSS',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'css' => array(
       'core/misc/drupal.base.css' => array(
         'every_page' => TRUE,
@@ -1872,7 +1872,7 @@ function system_library_info() {
   );
   $libraries['drupal.tableselect'] = array(
     'title' => 'Tableselect',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/tableselect.js' => array(),
     ),
@@ -1883,7 +1883,7 @@ function system_library_info() {
   );
   $libraries['drupal.tableheader'] = array(
     'title' => 'Table header',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/tableheader.js' => array(),
     ),
@@ -1897,7 +1897,7 @@ function system_library_info() {
   );
   $libraries['drupal.timezone'] = array(
     'title' => 'Timezone',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/timezone.js' => array(),
     ),
@@ -1908,7 +1908,7 @@ function system_library_info() {
   );
   $libraries['drupal.machine-name'] = array(
     'title' => 'Machine name',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/machine-name.js' => array(),
     ),
@@ -1922,7 +1922,7 @@ function system_library_info() {
 
   $libraries['drupal.system'] = array(
     'title' => 'System',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'system') . '/system.js' => array(),
     ),
@@ -1935,7 +1935,7 @@ function system_library_info() {
   );
   $libraries['drupal.system.modules'] = array(
     'title' => 'System modules',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'system') . '/system.modules.js' => array(),
     ),
@@ -1969,7 +1969,7 @@ function system_stream_wrappers() {
   );
 
   // Only register the private file stream wrapper if a file path has been set.
-  if (Drupal::config('system.file')->get('path.private')) {
+  if (\Drupal::config('system.file')->get('path.private')) {
     $wrappers['private'] = array(
       'name' => t('Private files'),
       'class' => 'Drupal\Core\StreamWrapper\PrivateStream',
@@ -2204,7 +2204,7 @@ function system_custom_theme() {
     $request = drupal_container()->get('request');
     $path = $request->attributes->get('_system_path');
     if (user_access('view the administration theme') && path_is_admin($path)) {
-      return Drupal::config('system.theme')->get('admin');
+      return \Drupal::config('system.theme')->get('admin');
     }
   }
 }
@@ -2213,7 +2213,7 @@ function system_custom_theme() {
  * Implements hook_form_FORM_ID_alter().
  */
 function system_form_user_form_alter(&$form, &$form_state) {
-  if (Drupal::config('system.date')->get('timezone.user.configurable')) {
+  if (\Drupal::config('system.date')->get('timezone.user.configurable')) {
     system_user_timezone($form, $form_state);
   }
 }
@@ -2222,7 +2222,7 @@ function system_form_user_form_alter(&$form, &$form_state) {
  * Implements hook_form_FORM_ID_alter().
  */
 function system_form_user_register_form_alter(&$form, &$form_state) {
-  $config = Drupal::config('system.date');
+  $config = \Drupal::config('system.date');
   if ($config->get('timezone.user.configurable') && $config->get('timezone.user.default') == DRUPAL_USER_TIMEZONE_SELECT) {
     system_user_timezone($form, $form_state);
   }
@@ -2232,7 +2232,7 @@ function system_form_user_register_form_alter(&$form, &$form_state) {
  * Implements hook_user_presave().
  */
 function system_user_presave(UserInterface $account) {
-  $config = Drupal::config('system.date');
+  $config = \Drupal::config('system.date');
   if ($config->get('timezone.user.configurable') && !$account->getTimeZone() && !$config->get('timezone.user.default')) {
     $account->timezone = $config->get('timezone.default');
   }
@@ -2242,7 +2242,7 @@ function system_user_presave(UserInterface $account) {
  * Implements hook_user_login().
  */
 function system_user_login($account) {
-  $config = Drupal::config('system.date');
+  $config = \Drupal::config('system.date');
   // If the user has a NULL time zone, notify them to set a time zone.
   if (!$account->getTimezone() && $config->get('timezone.user.configurable') && $config->get('timezone.user.warn')) {
     drupal_set_message(t('Configure your <a href="@user-edit">account time zone setting</a>.', array('@user-edit' => url("user/$account->id()/edit", array('query' => drupal_get_destination(), 'fragment' => 'edit-timezone')))));
@@ -2264,7 +2264,7 @@ function system_user_timezone(&$form, &$form_state) {
   $form['timezone']['timezone'] = array(
     '#type' => 'select',
     '#title' => t('Time zone'),
-    '#default_value' => $account->getTimezone() ? $account->getTimezone() : Drupal::config('system.date')->get('timezone.default'),
+    '#default_value' => $account->getTimezone() ? $account->getTimezone() : \Drupal::config('system.date')->get('timezone.default'),
     '#options' => system_time_zones($account->id() != $user->id()),
     '#description' => t('Select the desired local time and time zone. Dates and times throughout this site will be displayed using this time zone.'),
   );
@@ -2367,7 +2367,7 @@ function system_get_info($type, $name = NULL) {
   $info = array();
   if ($type == 'module') {
     $data = system_rebuild_module_data();
-    foreach (Drupal::moduleHandler()->getModuleList() as $module => $filename) {
+    foreach (\Drupal::moduleHandler()->getModuleList() as $module => $filename) {
       if (isset($data[$module])) {
         $info[$module] = $data[$module]->info;
       }
@@ -2501,8 +2501,8 @@ function system_rebuild_module_data() {
     $files = array();
     ksort($modules);
     // Add name, status, weight, and schema version.
-    $enabled_modules = (array) Drupal::config('system.module')->get('enabled');
-    $disabled_modules = (array) Drupal::config('system.module.disabled')->get();
+    $enabled_modules = (array) \Drupal::config('system.module')->get('enabled');
+    $disabled_modules = (array) \Drupal::config('system.module.disabled')->get();
     $all_modules = $enabled_modules + $disabled_modules;
     foreach ($modules as $module => $record) {
       $record->name = $module;
@@ -2511,12 +2511,12 @@ function system_rebuild_module_data() {
       $record->schema_version = SCHEMA_UNINSTALLED;
       $files[$module] = $record->filename;
     }
-    $modules = Drupal::moduleHandler()->buildModuleDependencies($modules);
+    $modules = \Drupal::moduleHandler()->buildModuleDependencies($modules);
     $modules_cache = $modules;
 
     // Store filenames to allow system_list() and drupal_get_filename() to
     // retrieve them without having to rebuild or scan the filesystem.
-    Drupal::state()->set('system.module.files', $files);
+    \Drupal::state()->set('system.module.files', $files);
   }
   return $modules_cache;
 }
@@ -2531,7 +2531,7 @@ function _system_rebuild_theme_data() {
   // Find themes
   $themes = drupal_system_listing('/^' . DRUPAL_PHP_FUNCTION_PATTERN . '\.info.yml$/', 'themes');
   // Allow modules to add further themes.
-  if ($module_themes = Drupal::moduleHandler()->invokeAll('system_theme_info')) {
+  if ($module_themes = \Drupal::moduleHandler()->invokeAll('system_theme_info')) {
     foreach ($module_themes as $name => $uri) {
       // @see file_scan_directory()
       $themes[$name] = (object) array(
@@ -2655,7 +2655,7 @@ function system_rebuild_theme_data() {
   //   based on the current config. Remove this code when themes have a proper
   //   installation status.
   // @see http://drupal.org/node/1067408
-  $enabled_themes = (array) Drupal::config('system.theme')->get('enabled');
+  $enabled_themes = (array) \Drupal::config('system.theme')->get('enabled');
   $files = array();
   foreach ($themes as $name => $theme) {
     $theme->status = (int) isset($enabled_themes[$name]);
@@ -2663,11 +2663,11 @@ function system_rebuild_theme_data() {
   }
   // Replace last known theme data state.
   // @todo Obsolete with proper installation status for themes.
-  Drupal::state()->set('system.theme.data', $themes);
+  \Drupal::state()->set('system.theme.data', $themes);
 
   // Store filenames to allow system_list() and drupal_get_filename() to
   // retrieve them without having to rebuild or scan the filesystem.
-  Drupal::state()->set('system.theme.files', $files);
+  \Drupal::state()->set('system.theme.files', $files);
 
   return $themes;
 }
@@ -2882,7 +2882,7 @@ function confirm_form($form, $question, $path, $description = NULL, $yes = NULL,
 function system_admin_compact_mode() {
   // PHP converts dots into underscores in cookie names to avoid problems with
   // its parser, so we use a converted cookie name.
-  return isset($_COOKIE['Drupal_visitor_admin_compact_mode']) ? $_COOKIE['Drupal_visitor_admin_compact_mode'] : Drupal::config('system.site')->get('admin_compact_mode');
+  return isset($_COOKIE['Drupal_visitor_admin_compact_mode']) ? $_COOKIE['Drupal_visitor_admin_compact_mode'] : \Drupal::config('system.site')->get('admin_compact_mode');
 }
 
 /**
@@ -2947,7 +2947,7 @@ function system_get_module_admin_tasks($module, $info) {
   }
 
   // Append link for permissions.
-  if (Drupal::moduleHandler()->implementsHook($module, 'permission')) {
+  if (\Drupal::moduleHandler()->implementsHook($module, 'permission')) {
     $item = menu_get_item('admin/people/permissions');
     if (!empty($item['access'])) {
       $item['link_path'] = $item['href'];
@@ -2969,7 +2969,7 @@ function system_get_module_admin_tasks($module, $info) {
  */
 function system_cron() {
   // Cleanup the flood.
-  Drupal::service('flood')->garbageCollection();
+  \Drupal::service('flood')->garbageCollection();
 
   foreach (Cache::getBins() as $cache_backend) {
     $cache_backend->garbageCollection();
@@ -2996,7 +2996,7 @@ function system_cron() {
  * Implements hook_mail().
  */
 function system_mail($key, &$message, $params) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $context = $params['context'];
 
@@ -3099,7 +3099,7 @@ function system_retrieve_file($url, $destination = NULL, $managed = FALSE, $repl
     }
   }
   try {
-    $data = Drupal::httpClient()
+    $data = \Drupal::httpClient()
       ->get($url)
       ->send()
       ->getBody(TRUE);
@@ -3143,8 +3143,8 @@ function system_run_automated_cron() {
   // If the site is not fully installed, suppress the automated cron run.
   // Otherwise it could be triggered prematurely by Ajax requests during
   // installation.
-  if (($threshold = Drupal::config('system.cron')->get('threshold.autorun')) > 0 && variable_get('install_task') == 'done') {
-    $cron_last = Drupal::state()->get('system.cron_last') ?: NULL;
+  if (($threshold = \Drupal::config('system.cron')->get('threshold.autorun')) > 0 && variable_get('install_task') == 'done') {
+    $cron_last = \Drupal::state()->get('system.cron_last') ?: NULL;
     if (!isset($cron_last) || (REQUEST_TIME - $cron_last > $threshold)) {
       drupal_cron_run();
     }
diff --git a/core/modules/system/system.tokens.inc b/core/modules/system/system.tokens.inc
index 2dca362d57eda7d2a5a7bb996e6174627ca6f996..4c27e2cc806a12c4ed540f16b951f13468c89afd 100644
--- a/core/modules/system/system.tokens.inc
+++ b/core/modules/system/system.tokens.inc
@@ -85,7 +85,7 @@ function system_token_info() {
  * Implements hook_tokens().
  */
 function system_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $url_options = array('absolute' => TRUE);
   if (isset($options['langcode'])) {
@@ -103,17 +103,17 @@ function system_tokens($type, $tokens, array $data = array(), array $options = a
     foreach ($tokens as $name => $original) {
       switch ($name) {
         case 'name':
-          $site_name = Drupal::config('system.site')->get('name');
+          $site_name = \Drupal::config('system.site')->get('name');
           $replacements[$original] = $sanitize ? check_plain($site_name) : $site_name;
           break;
 
         case 'slogan':
-          $slogan = Drupal::config('system.site')->get('slogan');
+          $slogan = \Drupal::config('system.site')->get('slogan');
           $replacements[$original] = $sanitize ? filter_xss_admin($slogan) : $slogan;
           break;
 
         case 'mail':
-          $replacements[$original] = Drupal::config('system.site')->get('mail');
+          $replacements[$original] = \Drupal::config('system.site')->get('mail');
           break;
 
         case 'url':
diff --git a/core/modules/system/tests/modules/batch_test/batch_test.module b/core/modules/system/tests/modules/batch_test/batch_test.module
index f2b54409cd271914c2eaf81b48d0d1a69c9f4526..3f7ffc7b7fe2f41b1f8f82429fd138f136224260 100644
--- a/core/modules/system/tests/modules/batch_test/batch_test.module
+++ b/core/modules/system/tests/modules/batch_test/batch_test.module
@@ -448,12 +448,12 @@ function _batch_test_theme_callback() {
  */
 function batch_test_stack($data = NULL, $reset = FALSE) {
   if ($reset) {
-    Drupal::state()->delete('batch_test.stack');
+    \Drupal::state()->delete('batch_test.stack');
   }
   if (!isset($data)) {
-    return Drupal::state()->get('batch_test.stack');
+    return \Drupal::state()->get('batch_test.stack');
   }
-  $stack = Drupal::state()->get('batch_test.stack');
+  $stack = \Drupal::state()->get('batch_test.stack');
   $stack[] = $data;
-  Drupal::state()->set('batch_test.stack', $stack);
+  \Drupal::state()->set('batch_test.stack', $stack);
 }
diff --git a/core/modules/system/tests/modules/common_test_cron_helper/common_test_cron_helper.module b/core/modules/system/tests/modules/common_test_cron_helper/common_test_cron_helper.module
index ef3ac8873cf82c209b4c38273705eb2463219259..ee280a3b044d9328b08b28815f4d318ee4e3d122 100644
--- a/core/modules/system/tests/modules/common_test_cron_helper/common_test_cron_helper.module
+++ b/core/modules/system/tests/modules/common_test_cron_helper/common_test_cron_helper.module
@@ -14,5 +14,5 @@
  * @see common_test_cron()
  */
 function common_test_cron_helper_cron() {
-  Drupal::state()->set('common_test.cron', 'success');
+  \Drupal::state()->set('common_test.cron', 'success');
 }
diff --git a/core/modules/system/tests/modules/design_test/design_test.module b/core/modules/system/tests/modules/design_test/design_test.module
index 24079c4fd35311ac3577ec0411c780ea243b4fc4..1b9266a933c7b4dca7f50b1395a0ba0bd2613e02 100644
--- a/core/modules/system/tests/modules/design_test/design_test.module
+++ b/core/modules/system/tests/modules/design_test/design_test.module
@@ -96,7 +96,7 @@ function design_test_menu_local_tasks_alter(&$data, $router_item, $root_path) {
     $actions = &$data['actions']['output'];
     // Determine the currently selected theme, if any.
     $selected_theme = drupal_container()->get('request')->query->get('theme');
-    $default_theme = Drupal::config('system.theme')->get('default');
+    $default_theme = \Drupal::config('system.theme')->get('default');
 
     // Expand all enabled themes into action links.
     $themes = list_themes();
diff --git a/core/modules/system/tests/modules/entity_cache_test/entity_cache_test.module b/core/modules/system/tests/modules/entity_cache_test/entity_cache_test.module
index 962114cd09302a44051c1e035155ca9940a4bf6f..e7041c4e50aea595640107f2765ebb17610cf83f 100644
--- a/core/modules/system/tests/modules/entity_cache_test/entity_cache_test.module
+++ b/core/modules/system/tests/modules/entity_cache_test/entity_cache_test.module
@@ -21,6 +21,6 @@ function entity_cache_test_watchdog($log_entry) {
     $info = entity_get_info('entity_cache_test');
     // Store the information in a system variable to analyze it later in the
     // test case.
-    Drupal::state()->set('entity_cache_test', $info);
+    \Drupal::state()->set('entity_cache_test', $info);
   }
 }
diff --git a/core/modules/system/tests/modules/entity_cache_test_dependency/entity_cache_test_dependency.module b/core/modules/system/tests/modules/entity_cache_test_dependency/entity_cache_test_dependency.module
index f2e9873c4704b3a372718c480e340cc42fcd0a96..004f531958ccfb0b840660eb669e3a1288fe4837 100644
--- a/core/modules/system/tests/modules/entity_cache_test_dependency/entity_cache_test_dependency.module
+++ b/core/modules/system/tests/modules/entity_cache_test_dependency/entity_cache_test_dependency.module
@@ -9,5 +9,5 @@
  * Implements hook_entity_info_alter().
  */
 function entity_cache_test_dependency_entity_info_alter(&$info) {
-  $info['entity_cache_test']['label'] = Drupal::state()->get('entity_cache_test.label') ?: 'Entity Cache Test';
+  $info['entity_cache_test']['label'] = \Drupal::state()->get('entity_cache_test.label') ?: 'Entity Cache Test';
 }
diff --git a/core/modules/system/tests/modules/entity_test/entity_test.module b/core/modules/system/tests/modules/entity_test/entity_test.module
index b4014704a4470026a308873f0dbbc367242a9457..88fc46e266390ffbada7069d7093c037cb19ff8d 100644
--- a/core/modules/system/tests/modules/entity_test/entity_test.module
+++ b/core/modules/system/tests/modules/entity_test/entity_test.module
@@ -59,7 +59,7 @@ function entity_test_entity_types($filter = NULL) {
  */
 function entity_test_entity_info_alter(&$info) {
   // Optionally specify a translation handler for testing translations.
-  if (Drupal::state()->get('entity_test.translation')) {
+  if (\Drupal::state()->get('entity_test.translation')) {
     foreach(entity_test_entity_types() as $entity_type) {
       $info[$entity_type]['translation'][$entity_type] = TRUE;
     }
@@ -79,9 +79,9 @@ function entity_test_entity_info_alter(&$info) {
  *   'entity_test'.
  */
 function entity_test_create_bundle($bundle, $text = NULL, $entity_type = 'entity_test') {
-  $bundles = Drupal::state()->get($entity_type . '.bundles') ?: array('entity_test' => array('label' => 'Entity Test Bundle'));
+  $bundles = \Drupal::state()->get($entity_type . '.bundles') ?: array('entity_test' => array('label' => 'Entity Test Bundle'));
   $bundles += array($bundle => array('label' => $text ? $text : $bundle));
-  Drupal::state()->set($entity_type . '.bundles', $bundles);
+  \Drupal::state()->set($entity_type . '.bundles', $bundles);
 
   entity_invoke_bundle_hook('create', $entity_type, $bundle);
 }
@@ -98,10 +98,10 @@ function entity_test_create_bundle($bundle, $text = NULL, $entity_type = 'entity
  *   'entity_test'.
  */
 function entity_test_rename_bundle($bundle_old, $bundle_new, $entity_type = 'entity_test') {
-  $bundles = Drupal::state()->get($entity_type . '.bundles') ?: array('entity_test' => array('label' => 'Entity Test Bundle'));
+  $bundles = \Drupal::state()->get($entity_type . '.bundles') ?: array('entity_test' => array('label' => 'Entity Test Bundle'));
   $bundles[$bundle_new] = $bundles[$bundle_old];
   unset($bundles[$bundle_old]);
-  Drupal::state()->set($entity_type . '.bundles', $bundles);
+  \Drupal::state()->set($entity_type . '.bundles', $bundles);
 
   entity_invoke_bundle_hook('rename', $entity_type, $bundle_old, $bundle_new);
 }
@@ -116,9 +116,9 @@ function entity_test_rename_bundle($bundle_old, $bundle_new, $entity_type = 'ent
  *   'entity_test'.
  */
 function entity_test_delete_bundle($bundle, $entity_type = 'entity_test') {
-  $bundles = Drupal::state()->get($entity_type . '.bundles') ?: array('entity_test' => array('label' => 'Entity Test Bundle'));
+  $bundles = \Drupal::state()->get($entity_type . '.bundles') ?: array('entity_test' => array('label' => 'Entity Test Bundle'));
   unset($bundles[$bundle]);
-  Drupal::state()->set($entity_type . '.bundles', $bundles);
+  \Drupal::state()->set($entity_type . '.bundles', $bundles);
 
   entity_invoke_bundle_hook('delete', $entity_type, $bundle);
 }
@@ -131,7 +131,7 @@ function entity_test_entity_bundle_info() {
   $entity_info = entity_get_info();
   foreach ($entity_info as $entity_type => $info) {
     if ($info['module'] == 'entity_test') {
-      $bundles[$entity_type] = Drupal::state()->get($entity_type . '.bundles') ?: array($entity_type => array('label' => 'Entity Test Bundle'));
+      $bundles[$entity_type] = \Drupal::state()->get($entity_type . '.bundles') ?: array($entity_type => array('label' => 'Entity Test Bundle'));
     }
   }
   return $bundles;
@@ -242,7 +242,7 @@ function entity_test_menu() {
  */
 function entity_test_form_node_form_alter(&$form, &$form_state, $form_id) {
   $langcode = $form_state['controller']->getFormLangcode($form_state);
-  Drupal::state()->set('entity_test.form_langcode', $langcode);
+  \Drupal::state()->set('entity_test.form_langcode', $langcode);
 }
 
 /**
@@ -259,7 +259,7 @@ function entity_test_form_node_form_alter(&$form, &$form_state, $form_id) {
 function entity_test_add($entity_type) {
   drupal_set_title(t('Create an @type', array('@type' => $entity_type)));
   $entity = entity_create($entity_type, array());
-  return Drupal::entityManager()->getForm($entity);
+  return \Drupal::entityManager()->getForm($entity);
 }
 
 /**
@@ -275,7 +275,7 @@ function entity_test_add($entity_type) {
  */
 function entity_test_edit(EntityInterface $entity) {
   drupal_set_title($entity->label(), PASS_THROUGH);
-  return Drupal::entityManager()->getForm($entity);
+  return \Drupal::entityManager()->getForm($entity);
 }
 
 /**
diff --git a/core/modules/system/tests/modules/menu_test/menu_test.module b/core/modules/system/tests/modules/menu_test/menu_test.module
index 36eef0023dc1514f40ef19a17cd1391ae364bdc2..833d4972371b77c72212e8aca960a767cee1dc59 100644
--- a/core/modules/system/tests/modules/menu_test/menu_test.module
+++ b/core/modules/system/tests/modules/menu_test/menu_test.module
@@ -444,7 +444,7 @@ function menu_test_local_action_dynamic_title($arg) {
  * several local tasks to menu-test/tasks.
  */
 function menu_test_menu_local_tasks(&$data, $router_item, $root_path) {
-  if (!Drupal::config('menu_test.settings')->get('tasks.add')) {
+  if (!\Drupal::config('menu_test.settings')->get('tasks.add')) {
     return;
   }
   if (strpos($router_item['tab_root'], 'menu-test/tasks/') === 0) {
@@ -474,7 +474,7 @@ function menu_test_menu_local_tasks(&$data, $router_item, $root_path) {
  * several local tasks to menu-test/tasks.
  */
 function menu_test_menu_local_tasks_alter(&$data, $router_item, $root_path) {
-  if (!Drupal::config('menu_test.settings')->get('tasks.alter')) {
+  if (!\Drupal::config('menu_test.settings')->get('tasks.alter')) {
     return;
   }
   if (strpos($router_item['tab_root'], 'menu-test/tasks/') === 0) {
@@ -547,7 +547,7 @@ function menu_test_callback() {
  * @see menu_test_menu().
  */
 function menu_test_menu_trail_callback() {
-  $menu_path = Drupal::state()->get('menu_test.menu_tree_set_path') ?: array();
+  $menu_path = \Drupal::state()->get('menu_test.menu_tree_set_path') ?: array();
   if (!empty($menu_path)) {
     menu_tree_set_path($menu_path['menu_name'], $menu_path['path']);
   }
@@ -566,8 +566,8 @@ function menu_test_custom_403_404_callback() {
   // When requested by one of the TrailTest tests, record the final
   // active trail now that the user has been redirected to the custom 403 or
   // 404 page.
-  if (Drupal::state()->get('menu_test.record_active_trail') ?: FALSE) {
-    Drupal::state()->set('menu_test.active_trail_final', menu_get_active_trail());
+  if (\Drupal::state()->get('menu_test.record_active_trail') ?: FALSE) {
+    \Drupal::state()->set('menu_test.active_trail_final', menu_get_active_trail());
   }
 
   return 'This is menu_test_custom_403_404_callback().';
@@ -617,7 +617,7 @@ function menu_test_theme_page_callback($inherited = FALSE) {
 function menu_test_theme_callback($argument) {
   // Test using the variable administrative theme.
   if ($argument == 'use-admin-theme') {
-    return Drupal::config('system.theme')->get('admin');
+    return \Drupal::config('system.theme')->get('admin');
   }
   // Test using a theme that exists, but may or may not be enabled.
   elseif ($argument == 'use-stark-theme') {
@@ -642,10 +642,10 @@ function menu_test_custom_theme() {
   // When requested by one of the MenuTrailTestCase tests, record the initial
   // active trail during Drupal's bootstrap (before the user is redirected to a
   // custom 403 or 404 page). See menu_test_custom_403_404_callback().
-  if (Drupal::state()->get('menu_test.record_active_trail') ?: FALSE) {
-    Drupal::state()->set('menu_test.active_trail_initial', menu_get_active_trail());
+  if (\Drupal::state()->get('menu_test.record_active_trail') ?: FALSE) {
+    \Drupal::state()->set('menu_test.active_trail_initial', menu_get_active_trail());
   }
-  if ($theme = Drupal::state()->get('menu_test.hook_custom_theme_name') ?: FALSE) {
+  if ($theme = \Drupal::state()->get('menu_test.hook_custom_theme_name') ?: FALSE) {
     return $theme;
   }
 }
diff --git a/core/modules/system/tests/modules/module_test/module_test.file.inc b/core/modules/system/tests/modules/module_test/module_test.file.inc
index 1929941e660a10b8f03174c936bfe3692fc97404..0842944ca68595749fa6bdae503dd43877c95052 100644
--- a/core/modules/system/tests/modules/module_test/module_test.file.inc
+++ b/core/modules/system/tests/modules/module_test/module_test.file.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * A file to test Drupal::moduleHandler()->getImplementations() loading includes.
+ * A file to test \Drupal::moduleHandler()->getImplementations() loading includes.
  */
 
 /**
diff --git a/core/modules/system/tests/modules/module_test/module_test.module b/core/modules/system/tests/modules/module_test/module_test.module
index 4e36d9b23d8d00f30ef58abdff58010de3946043..9a2647e07616c811149a4139eb449906ca05bc9f 100644
--- a/core/modules/system/tests/modules/module_test/module_test.module
+++ b/core/modules/system/tests/modules/module_test/module_test.module
@@ -15,7 +15,7 @@ function module_test_permission() {
  * Manipulate module dependencies to test dependency chains.
  */
 function module_test_system_info_alter(&$info, $file, $type) {
-  if (Drupal::state()->get('module_test.dependency') == 'missing dependency') {
+  if (\Drupal::state()->get('module_test.dependency') == 'missing dependency') {
     if ($file->name == 'forum') {
       // Make forum module depend on ban.
       $info['dependencies'][] = 'ban';
@@ -25,7 +25,7 @@ function module_test_system_info_alter(&$info, $file, $type) {
       $info['dependencies'][] = 'foo';
     }
   }
-  elseif (Drupal::state()->get('module_test.dependency') == 'dependency') {
+  elseif (\Drupal::state()->get('module_test.dependency') == 'dependency') {
     if ($file->name == 'forum') {
       // Make the forum module depend on ban.
       $info['dependencies'][] = 'ban';
@@ -35,7 +35,7 @@ function module_test_system_info_alter(&$info, $file, $type) {
       $info['dependencies'][] = 'xmlrpc';
     }
   }
-  elseif (Drupal::state()->get('module_test.dependency') == 'version dependency') {
+  elseif (\Drupal::state()->get('module_test.dependency') == 'version dependency') {
     if ($file->name == 'forum') {
       // Make the forum module depend on ban.
       $info['dependencies'][] = 'ban';
@@ -110,7 +110,7 @@ function module_test_hook_dynamic_loading_invoke() {
  * return 'success!'.
  */
 function module_test_hook_dynamic_loading_invoke_all() {
-  $result = Drupal::moduleHandler()->invokeAll('test_hook');
+  $result = \Drupal::moduleHandler()->invokeAll('test_hook');
   return $result['module_test'];
 }
 
@@ -130,7 +130,7 @@ function module_test_hook_dynamic_loading_invoke_all_during_load($param) {
  * @see module_test_menu().
  */
 function module_test_load($param) {
-  $result = Drupal::moduleHandler()->invokeAll('test_hook');
+  $result = \Drupal::moduleHandler()->invokeAll('test_hook');
   return $result[$param];
 }
 
@@ -155,7 +155,7 @@ function module_test_class_loading() {
 function module_test_modules_enabled($modules) {
   // Record the ordered list of modules that were passed in to this hook so we
   // can check that the modules were enabled in the correct sequence.
-  Drupal::state()->set('system_test.module_enable_order', $modules);
+  \Drupal::state()->set('system_test.module_enable_order', $modules);
 }
 
 /**
@@ -164,7 +164,7 @@ function module_test_modules_enabled($modules) {
 function module_test_modules_disabled($modules) {
   // Record the ordered list of modules that were passed in to this hook so we
   // can check that the modules were disabled in the correct sequence.
-  Drupal::state()->set('module_test.disable_order', $modules);
+  \Drupal::state()->set('module_test.disable_order', $modules);
 }
 
 /**
@@ -173,5 +173,5 @@ function module_test_modules_disabled($modules) {
 function module_test_modules_uninstalled($modules) {
   // Record the ordered list of modules that were passed in to this hook so we
   // can check that the modules were uninstalled in the correct sequence.
-  Drupal::state()->set('module_test.uninstall_order', $modules);
+  \Drupal::state()->set('module_test.uninstall_order', $modules);
 }
diff --git a/core/modules/system/tests/modules/path_test/path_test.module b/core/modules/system/tests/modules/path_test/path_test.module
index 6f4d580ae0f0c08d67cceedef35316215c95d142..df03931255d4d966b3fe855727dd2418378c7c62 100644
--- a/core/modules/system/tests/modules/path_test/path_test.module
+++ b/core/modules/system/tests/modules/path_test/path_test.module
@@ -9,14 +9,14 @@
  * Resets the path test results.
  */
 function path_test_reset() {
-  Drupal::state()->set('path_test.results', array());
+  \Drupal::state()->set('path_test.results', array());
 }
 
 /**
  * Implements hook_path_update().
  */
 function path_test_path_update($path) {
-  $results = Drupal::state()->get('path_test.results') ?: array();
+  $results = \Drupal::state()->get('path_test.results') ?: array();
   $results['hook_path_update'] = $path;
-  Drupal::state()->set('path_test.results', $results);
+  \Drupal::state()->set('path_test.results', $results);
 }
diff --git a/core/modules/system/tests/modules/system_test/system_test.module b/core/modules/system/tests/modules/system_test/system_test.module
index ea10a04b74f1571aeff4787eba7fa8ecedc02ab0..2236873f9ab00b30d070a5d7001540b50d56e6db 100644
--- a/core/modules/system/tests/modules/system_test/system_test.module
+++ b/core/modules/system/tests/modules/system_test/system_test.module
@@ -90,7 +90,7 @@ function system_test_set_header() {
  * Implements hook_modules_installed().
  */
 function system_test_modules_installed($modules) {
-  if (Drupal::state()->get('system_test.verbose_module_hooks')) {
+  if (\Drupal::state()->get('system_test.verbose_module_hooks')) {
     foreach ($modules as $module) {
       drupal_set_message(t('hook_modules_installed fired for @module', array('@module' => $module)));
     }
@@ -101,7 +101,7 @@ function system_test_modules_installed($modules) {
  * Implements hook_modules_enabled().
  */
 function system_test_modules_enabled($modules) {
-  if (Drupal::state()->get('system_test.verbose_module_hooks')) {
+  if (\Drupal::state()->get('system_test.verbose_module_hooks')) {
     foreach ($modules as $module) {
       drupal_set_message(t('hook_modules_enabled fired for @module', array('@module' => $module)));
     }
@@ -112,7 +112,7 @@ function system_test_modules_enabled($modules) {
  * Implements hook_modules_disabled().
  */
 function system_test_modules_disabled($modules) {
-  if (Drupal::state()->get('system_test.verbose_module_hooks')) {
+  if (\Drupal::state()->get('system_test.verbose_module_hooks')) {
     foreach ($modules as $module) {
       drupal_set_message(t('hook_modules_disabled fired for @module', array('@module' => $module)));
     }
@@ -123,7 +123,7 @@ function system_test_modules_disabled($modules) {
  * Implements hook_modules_uninstalled().
  */
 function system_test_modules_uninstalled($modules) {
-  if (Drupal::state()->get('system_test.verbose_module_hooks')) {
+  if (\Drupal::state()->get('system_test.verbose_module_hooks')) {
     foreach ($modules as $module) {
       drupal_set_message(t('hook_modules_uninstalled fired for @module', array('@module' => $module)));
     }
@@ -136,11 +136,11 @@ function system_test_modules_uninstalled($modules) {
 function system_test_system_info_alter(&$info, $file, $type) {
   // We need a static otherwise the last test will fail to alter common_test.
   static $test;
-  if (($dependencies = Drupal::state()->get('system_test.dependencies')) || $test) {
+  if (($dependencies = \Drupal::state()->get('system_test.dependencies')) || $test) {
     if ($file->name == 'module_test') {
       $info['hidden'] = FALSE;
       $info['dependencies'][] = array_shift($dependencies);
-      Drupal::state()->set('system_test.dependencies', $dependencies);
+      \Drupal::state()->set('system_test.dependencies', $dependencies);
       $test = TRUE;
     }
     if ($file->name == 'common_test') {
@@ -212,7 +212,7 @@ function system_test_page_build(&$page) {
     drupal_set_page_content();
   }
   // Used by FrontPageTestCase to get the results of drupal_is_front_page().
-  $frontpage = Drupal::state()->get('system_test.front_page_output') ?: 0;
+  $frontpage = \Drupal::state()->get('system_test.front_page_output') ?: 0;
   if ($frontpage && drupal_is_front_page()) {
     drupal_set_message(t('On front page.'));
   }
diff --git a/core/modules/system/tests/modules/update_script_test/update_script_test.install b/core/modules/system/tests/modules/update_script_test/update_script_test.install
index c5c9e590ef132095881b017cf5bab690f02f90c5..594dfa35024953854f21906396613b55c756abbe 100644
--- a/core/modules/system/tests/modules/update_script_test/update_script_test.install
+++ b/core/modules/system/tests/modules/update_script_test/update_script_test.install
@@ -13,7 +13,7 @@ function update_script_test_requirements($phase) {
 
   if ($phase == 'update') {
     // Set a requirements warning or error when the test requests it.
-    $requirement_type = Drupal::config('update_script_test.settings')->get('requirement_type');
+    $requirement_type = \Drupal::config('update_script_test.settings')->get('requirement_type');
     switch ($requirement_type) {
       case REQUIREMENT_WARNING:
         $requirements['update_script_test'] = array(
diff --git a/core/modules/system/tests/modules/update_test_1/update_test_1.install b/core/modules/system/tests/modules/update_test_1/update_test_1.install
index 3ac73db552f1db7aed38dbb2398b1d284f6273a7..bfb7170d811862ba3de38a01ec65c76cedec6a44 100644
--- a/core/modules/system/tests/modules/update_test_1/update_test_1.install
+++ b/core/modules/system/tests/modules/update_test_1/update_test_1.install
@@ -11,7 +11,7 @@
  * @see update_test_2_update_dependencies()
  */
 function update_test_1_update_dependencies() {
-  Drupal::state()->set('update_test_1_update_dependencies_run', TRUE);
+  \Drupal::state()->set('update_test_1_update_dependencies_run', TRUE);
   // These dependencies are used in combination with those declared in
   // update_test_2_update_dependencies() for the sole purpose of testing that
   // the results of hook_update_dependencies() are collected correctly and have
diff --git a/core/modules/taxonomy/taxonomy.install b/core/modules/taxonomy/taxonomy.install
index 7648ba0454fbc622ecb837eb2945db2ee95c9145..476ab2e1256d4c24b50f2df6371550ee95a056b3 100644
--- a/core/modules/taxonomy/taxonomy.install
+++ b/core/modules/taxonomy/taxonomy.install
@@ -13,7 +13,7 @@
  * Implements hook_uninstall().
  */
 function taxonomy_uninstall() {
-  Drupal::entityManager()->addNamespaces(new ArrayIterator(array(
+  \Drupal::entityManager()->addNamespaces(new ArrayIterator(array(
     'Drupal\taxonomy' => DRUPAL_ROOT . '/core/modules/taxonomy/lib',
   )));
   drupal_classloader_register('taxonomy', 'core/modules/taxonomy');
@@ -323,7 +323,7 @@ function taxonomy_update_8005() {
 
   $result = db_query('SELECT * FROM {taxonomy_vocabulary}');
   foreach ($result as $vocabulary) {
-    $config = Drupal::config('taxonomy.vocabulary.' . $vocabulary->machine_name)
+    $config = \Drupal::config('taxonomy.vocabulary.' . $vocabulary->machine_name)
       ->set('vid', $vocabulary->machine_name)
       ->set('name', $vocabulary->name)
       ->set('uuid', !empty($vocabulary->uuid) ? $vocabulary->uuid : $uuid->generate())
@@ -365,7 +365,7 @@ function taxonomy_update_8006() {
  */
 function taxonomy_update_8007() {
   foreach (config_get_storage_names_with_prefix('field.field.') as $config_name) {
-    $field_config = Drupal::config($config_name);
+    $field_config = \Drupal::config($config_name);
     // Only update taxonomy reference fields that use the default SQL storage.
     if ($field_config->get('type') == 'taxonomy_term_reference') {
       $field = new Field($field_config->get());
diff --git a/core/modules/taxonomy/taxonomy.module b/core/modules/taxonomy/taxonomy.module
index e14ed580ff8a4783222e4524b18f7a3811bec728..1df57d34307bfdc050ecdfc0a89d12543f5b28d7 100644
--- a/core/modules/taxonomy/taxonomy.module
+++ b/core/modules/taxonomy/taxonomy.module
@@ -114,7 +114,7 @@ function taxonomy_permission() {
 function taxonomy_entity_bundle_info() {
   $bundles = array();
   foreach (taxonomy_vocabulary_get_names() as $id) {
-    $config = Drupal::config('taxonomy.vocabulary.' . $id);
+    $config = \Drupal::config('taxonomy.vocabulary.' . $id);
     $bundles['taxonomy_term'][$id]['label'] = $config->get('name');
   }
   return $bundles;
@@ -182,7 +182,7 @@ function taxonomy_field_extra_fields() {
  *   An array of nids matching the query.
  */
 function taxonomy_select_nodes($tid, $pager = TRUE, $limit = FALSE, $order = array('t.sticky' => 'DESC', 't.created' => 'DESC')) {
-  if (!Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
+  if (!\Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
     return array();
   }
   $query = db_select('taxonomy_index', 't');
@@ -474,7 +474,7 @@ function taxonomy_term_is_page(Term $term) {
  * Clear all static cache variables for terms.
  */
 function taxonomy_terms_static_reset() {
-  Drupal::entityManager()->getStorageController('taxonomy_term')->resetCache();
+  \Drupal::entityManager()->getStorageController('taxonomy_term')->resetCache();
 }
 
 /**
@@ -484,7 +484,7 @@ function taxonomy_terms_static_reset() {
  *   An array of ids to reset in entity controller cache.
  */
 function taxonomy_vocabulary_static_reset(array $ids = NULL) {
-  Drupal::entityManager()->getStorageController('taxonomy_vocabulary')->resetCache($ids);
+  \Drupal::entityManager()->getStorageController('taxonomy_vocabulary')->resetCache($ids);
 }
 
 /**
@@ -1107,7 +1107,7 @@ function taxonomy_node_insert(EntityInterface $node) {
 function taxonomy_build_node_index($node) {
   // We maintain a denormalized table of term/node relationships, containing
   // only data for current, published nodes.
-  if (!Drupal::config('taxonomy.settings')->get('maintain_index_table') || !(Drupal::entityManager()->getStorageController('node') instanceof DatabaseStorageController)) {
+  if (!\Drupal::config('taxonomy.settings')->get('maintain_index_table') || !(\Drupal::entityManager()->getStorageController('node') instanceof DatabaseStorageController)) {
     return;
   }
 
@@ -1170,7 +1170,7 @@ function taxonomy_node_predelete(EntityInterface $node) {
  *   The node entity.
  */
 function taxonomy_delete_node_index(EntityInterface $node) {
-  if (Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
+  if (\Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
     db_delete('taxonomy_index')->condition('nid', $node->id())->execute();
   }
 }
@@ -1179,7 +1179,7 @@ function taxonomy_delete_node_index(EntityInterface $node) {
  * Implements hook_taxonomy_term_delete().
  */
 function taxonomy_taxonomy_term_delete(Term $term) {
-  if (Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
+  if (\Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
     // Clean up the {taxonomy_index} table when terms are deleted.
     db_delete('taxonomy_index')->condition('tid', $term->id())->execute();
   }
@@ -1195,7 +1195,7 @@ function taxonomy_taxonomy_term_delete(Term $term) {
 function taxonomy_library_info() {
   $libraries['drupal.taxonomy'] = array(
     'title' => 'Taxonomy',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'taxonomy') . '/taxonomy.js' => array(),
     ),
diff --git a/core/modules/taxonomy/taxonomy.pages.inc b/core/modules/taxonomy/taxonomy.pages.inc
index f6ffee01e04a05c1cd78af41150ecd37764f4d58..a2fc46733fdb92d6021c603df879a6ef3f573909 100644
--- a/core/modules/taxonomy/taxonomy.pages.inc
+++ b/core/modules/taxonomy/taxonomy.pages.inc
@@ -42,7 +42,7 @@ function taxonomy_term_page(Term $term) {
   }
 
   $build['taxonomy_terms'] = taxonomy_term_view_multiple(array($term->id() => $term));
-  if ($nids = taxonomy_select_nodes($term->id(), TRUE, Drupal::config('node.settings')->get('items_per_page'))) {
+  if ($nids = taxonomy_select_nodes($term->id(), TRUE, \Drupal::config('node.settings')->get('items_per_page'))) {
     $nodes = node_load_multiple($nids);
     $build['nodes'] = node_view_multiple($nodes);
     $build['pager'] = array(
@@ -68,11 +68,11 @@ function taxonomy_term_page(Term $term) {
  */
 function taxonomy_term_feed(Term $term) {
   $channel['link'] = url('taxonomy/term/' . $term->id(), array('absolute' => TRUE));
-  $channel['title'] = Drupal::config('system.site')->get('name') . ' - ' . $term->label();
+  $channel['title'] = \Drupal::config('system.site')->get('name') . ' - ' . $term->label();
   // Only display the description if we have a single term, to avoid clutter and confusion.
   // HTML will be removed from feed description.
   $channel['description'] = check_markup($term->description->value, $term->format->value, '', TRUE);
-  $nids = taxonomy_select_nodes($term->id(), FALSE, Drupal::config('system.rss')->get('items.limit'));
+  $nids = taxonomy_select_nodes($term->id(), FALSE, \Drupal::config('system.rss')->get('items.limit'));
 
   return node_feed($nids, $channel);
 }
diff --git a/core/modules/taxonomy/taxonomy.tokens.inc b/core/modules/taxonomy/taxonomy.tokens.inc
index 308f66cac354e41953c46b0fb4ce666c3f5d69e2..ec94447c5630f9850e8c16dba441138323d9a494 100644
--- a/core/modules/taxonomy/taxonomy.tokens.inc
+++ b/core/modules/taxonomy/taxonomy.tokens.inc
@@ -89,7 +89,7 @@ function taxonomy_token_info() {
  * Implements hook_tokens().
  */
 function taxonomy_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $replacements = array();
   $sanitize = !empty($options['sanitize']);
diff --git a/core/modules/taxonomy/taxonomy.views.inc b/core/modules/taxonomy/taxonomy.views.inc
index c33b697cd6880d2c84b2f2f0087774122ca6b0c0..4e9f27cdd8d80b4eff907ac3fb800a920707d78f 100644
--- a/core/modules/taxonomy/taxonomy.views.inc
+++ b/core/modules/taxonomy/taxonomy.views.inc
@@ -248,7 +248,7 @@ function taxonomy_views_data() {
   );
 
   // Content translation field.
-  if (Drupal::moduleHandler()->moduleExists('content_translation')) {
+  if (\Drupal::moduleHandler()->moduleExists('content_translation')) {
     $data['taxonomy_term_data']['translation_link'] = array(
       'title' => t('Translation link'),
       'help' => t('Provide a link to the translations overview for taxonomy terms.'),
diff --git a/core/modules/telephone/telephone.module b/core/modules/telephone/telephone.module
index 5445c5b12b04b4be43b0e7d631d02788409fcb5b..2d2bd355c858b4c53b5d3ff4b668dca264e5c409 100644
--- a/core/modules/telephone/telephone.module
+++ b/core/modules/telephone/telephone.module
@@ -9,7 +9,7 @@
  * Implements hook_field_info_alter().
  */
 function telephone_field_info_alter(&$info) {
-  if (Drupal::moduleHandler()->moduleExists('text')) {
+  if (\Drupal::moduleHandler()->moduleExists('text')) {
     $info['telephone']['default_formatter'] = 'text_plain';
   }
 }
diff --git a/core/modules/text/text.module b/core/modules/text/text.module
index 85cea7a712fc80309ead6ab59be26c4b140ef352..297e60ecab2c99b0db175f1a4090020c78be54f9 100644
--- a/core/modules/text/text.module
+++ b/core/modules/text/text.module
@@ -13,7 +13,7 @@
 function text_library_info() {
   $libraries['drupal.text'] = array(
     'title' => 'Text',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'text') . '/text.js' => array(),
     ),
@@ -65,7 +65,7 @@ function text_help($path, $arg) {
 function text_summary($text, $format = NULL, $size = NULL) {
 
   if (!isset($size)) {
-    $size = Drupal::config('text.settings')->get('default_summary_length');
+    $size = \Drupal::config('text.settings')->get('default_summary_length');
   }
 
   // Find where the delimiter is in the body
diff --git a/core/modules/toolbar/toolbar.module b/core/modules/toolbar/toolbar.module
index 43ad735d2f9afc1ea444be2bf874eeaf128c562a..604e04dfaa991fd5a6e940a1a50b203167227f0c 100644
--- a/core/modules/toolbar/toolbar.module
+++ b/core/modules/toolbar/toolbar.module
@@ -199,7 +199,7 @@ function ($object) {
   }
 
   // Get toolbar items from all modules that implement hook_toolbar().
-  $items = Drupal::moduleHandler()->invokeAll('toolbar');
+  $items = \Drupal::moduleHandler()->invokeAll('toolbar');
   // Allow for altering of hook_toolbar().
   drupal_alter('toolbar', $items);
   // Sort the children.
@@ -473,7 +473,7 @@ function toolbar_toolbar() {
  */
 function toolbar_get_menu_tree() {
   $tree = array();
-  $query = Drupal::entityQuery('menu_link')
+  $query = \Drupal::entityQuery('menu_link')
     ->condition('menu_name', 'admin')
     ->condition('module', 'system')
     ->condition('link_path', 'admin');
@@ -585,7 +585,7 @@ function toolbar_in_active_trail($path) {
 function toolbar_library_info() {
   $libraries['toolbar'] = array(
     'title' => 'Toolbar',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'toolbar') . '/js/toolbar.js' => array(),
     ),
@@ -609,7 +609,7 @@ function toolbar_library_info() {
 
   $libraries['toolbar.menu'] = array(
     'title' => 'Toolbar nested accordion menus.',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'toolbar') . '/js/toolbar.menu.js' => array(),
     ),
@@ -630,7 +630,7 @@ function toolbar_library_info() {
  * Returns the hash of the per-user rendered toolbar subtrees.
  */
 function _toolbar_get_subtree_hash() {
-  $user = Drupal::currentUser();
+  $user = \Drupal::currentUser();
   $cid = $user->id() . ':' . language(Language::TYPE_INTERFACE)->id;
   if ($cache = cache('toolbar')->get($cid)) {
     $hash = $cache->data;
diff --git a/core/modules/tour/tour.api.php b/core/modules/tour/tour.api.php
index 1836a1398dbcd71f5bc513f52ea431b8a343e429..db0312f3b9e57f5664770a55a5949eec4aa73511 100644
--- a/core/modules/tour/tour.api.php
+++ b/core/modules/tour/tour.api.php
@@ -72,7 +72,7 @@ function hook_tour_presave($entity) {
  *   The tour object being inserted.
  */
 function hook_tour_insert($entity) {
-  Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
+  \Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
   cache('cache_tour')->deleteTags(array('tour_items'));
 }
 
@@ -83,6 +83,6 @@ function hook_tour_insert($entity) {
  *   The tour object being updated.
  */
 function hook_tour_update($entity) {
-  Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
+  \Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
   cache('cache_tour')->deleteTags(array('tour_items'));
 }
diff --git a/core/modules/tour/tour.module b/core/modules/tour/tour.module
index 9cb4f64b96870c20766611aafb5b9e09dd0828af..4e410c0242542b88f14d82146e5fa718e6eae354 100644
--- a/core/modules/tour/tour.module
+++ b/core/modules/tour/tour.module
@@ -26,7 +26,7 @@ function tour_library_info() {
 
   $libraries['tour'] = array(
     'title' => 'Tour',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       // Add the JavaScript, with a group and weight such that it will run
       // before modules/overlay/overlay-parent.js.
@@ -44,7 +44,7 @@ function tour_library_info() {
 
   $libraries['tour-styling'] = array(
     'title' => 'Tour',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'css' => array(
       $path . '/css/tour.module.css' => array('media' => 'screen'),
     )
@@ -73,7 +73,7 @@ function tour_library_info() {
  * Implements hook_toolbar().
  */
 function tour_toolbar() {
-  if (!Drupal::currentUser()->hasPermission('access tour')) {
+  if (!\Drupal::currentUser()->hasPermission('access tour')) {
     return;
   }
 
@@ -107,7 +107,7 @@ function tour_toolbar() {
  * Implements hook_preprocess_HOOK() for page.tpl.php.
  */
 function tour_preprocess_page(&$variables) {
-  if (!Drupal::currentUser()->hasPermission('access tour')) {
+  if (!\Drupal::currentUser()->hasPermission('access tour')) {
     return;
   }
 
@@ -117,7 +117,7 @@ function tour_preprocess_page(&$variables) {
   // Load all of the items and match on path.
   $tours = entity_load_multiple('tour');
 
-  $path_alias = drupal_strtolower(Drupal::service('path.alias_manager')->getPathAlias($path));
+  $path_alias = drupal_strtolower(\Drupal::service('path.alias_manager')->getPathAlias($path));
   foreach ($tours as $tour_id => $tour) {
     // @todo Replace this with an entity query that does path matching when
     // http://drupal.org/node/1918768 lands.
@@ -136,12 +136,12 @@ function tour_preprocess_page(&$variables) {
  * Implements hook_tour_insert().
  */
 function tour_tour_insert($entity) {
-  Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
+  \Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
 }
 
 /**
  * Implements hook_tour_update().
  */
 function tour_tour_update($entity) {
-  Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
+  \Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
 }
diff --git a/core/modules/tracker/tracker.install b/core/modules/tracker/tracker.install
index 841d74ac76a4914ac15a1277c5f4c198008dcf57..daa29839ff3a971103466131904d05accb5cd433 100644
--- a/core/modules/tracker/tracker.install
+++ b/core/modules/tracker/tracker.install
@@ -9,7 +9,7 @@
  * Implements hook_uninstall().
  */
 function tracker_uninstall() {
-  Drupal::state()->delete('tracker.index_nid');
+  \Drupal::state()->delete('tracker.index_nid');
 }
 
 /**
@@ -18,7 +18,7 @@ function tracker_uninstall() {
 function tracker_enable() {
   $max_nid = db_query('SELECT MAX(nid) FROM {node}')->fetchField();
   if ($max_nid != 0) {
-    Drupal::state()->set('tracker.index_nid', $max_nid);
+    \Drupal::state()->set('tracker.index_nid', $max_nid);
     // To avoid timing out while attempting to do a complete indexing, we
     // simply call our cron job to remove stale records and begin the process.
     tracker_cron();
diff --git a/core/modules/tracker/tracker.module b/core/modules/tracker/tracker.module
index 80b0d5ace0cbb6f359cedcd8b9c8af2d9fb3d1ab..b17b11fe094841b5bb0de93190c86763a7f872f4 100644
--- a/core/modules/tracker/tracker.module
+++ b/core/modules/tracker/tracker.module
@@ -81,10 +81,10 @@ function tracker_menu() {
  * process, 'tracker.index_nid' will be 0.
  */
 function tracker_cron() {
-  $state = Drupal::state();
+  $state = \Drupal::state();
   $max_nid = $state->get('tracker.index_nid') ?: 0;
   if ($max_nid > 0) {
-    $batch_size = Drupal::config('tracker.settings')->get('cron_index_limit');
+    $batch_size = \Drupal::config('tracker.settings')->get('cron_index_limit');
     $last_nid = FALSE;
     // @todo This should be actually filtering on the desired language and just
     //   fall back to the default language.
@@ -173,7 +173,7 @@ function tracker_cron() {
  */
 function _tracker_myrecent_access(AccountInterface $account) {
   // This path is only allowed for authenticated users looking at their own content.
-  return $account->id() && (Drupal::currentUser()->id() == $account->id()) && $account->hasPermission('access content');
+  return $account->id() && (\Drupal::currentUser()->id() == $account->id()) && $account->hasPermission('access content');
 }
 
 /**
diff --git a/core/modules/translation/translation.module b/core/modules/translation/translation.module
index f1d7075290691be59fdcac04f832b58e776674bd..f9d7a623a21b91005e474eb6add6536ce4f15321 100644
--- a/core/modules/translation/translation.module
+++ b/core/modules/translation/translation.module
@@ -98,7 +98,7 @@ function _translation_tab_access(NodeInterface $node) {
  * Implements hook_admin_paths().
  */
 function translation_admin_paths() {
-  if (Drupal::config('node.settings')->get('use_admin_theme')) {
+  if (\Drupal::config('node.settings')->get('use_admin_theme')) {
     $paths = array(
       'node/*/translate' => TRUE,
     );
@@ -124,7 +124,7 @@ function translation_permission() {
  * Implements hook_node_create_access().
  */
 function translation_node_create_access($account) {
-  $query = Drupal::request()->query;
+  $query = \Drupal::request()->query;
   $translation = $query->get('translation');
   $target = $query->get('target');
   $request_has_translation_arg = !empty($translation) && !empty($target) && is_numeric($translation);
@@ -152,7 +152,7 @@ function translation_node_create_access($account) {
 function translation_user_can_translate_node($node, $account = NULL) {
   // If no user object is supplied, the access check is for the current user.
   if (empty($account)) {
-    $account = Drupal::currentUser();
+    $account = \Drupal::currentUser();
   }
   return node_access('view', $node, $account) && (user_access('translate all content', $account) || ($node->getAuthorId() == $account->id() && user_access('translate own content', $account)));
 }
@@ -276,7 +276,7 @@ function translation_node_view(EntityInterface $node, EntityDisplay $display, $v
     // only for configurable language types and interface language is the only
     // configurable language type in core, we use it as default. Contributed
     // modules can change this behavior by setting the system variable below.
-    $type = Drupal::config('translation.settings')->get('language_type');
+    $type = \Drupal::config('translation.settings')->get('language_type');
     $custom_links = language_negotiation_get_switch_links($type, 'node/' . $node->id());
     $links = array();
 
@@ -319,7 +319,7 @@ function translation_node_view(EntityInterface $node, EntityDisplay $display, $v
  * Implements hook_node_prepare_form().
  */
 function translation_node_prepare_form(NodeInterface $node, $form_display, $operation, array &$form_state) {
-  $query = Drupal::request()->query;
+  $query = \Drupal::request()->query;
   $translation = $query->get('translation');
   $target = $query->get('target');
   // Only act if we are dealing with a content type supporting translations.
@@ -555,7 +555,7 @@ function translation_path_get_translations($path) {
  * Replaces links with pointers to translated versions of the content.
  */
 function translation_language_switch_links_alter(array &$links, $type, $path) {
-  $language_type = Drupal::config('translation.settings')->get('language_type');
+  $language_type = \Drupal::config('translation.settings')->get('language_type');
   if ($type == $language_type && preg_match("!^node/(\d+)(/.+|)!", $path, $matches)) {
     $node = node_load((int) $matches[1]);
 
@@ -594,7 +594,7 @@ function translation_language_switch_links_alter(array &$links, $type, $path) {
 function translation_library_info() {
   $libraries['drupal.translation'] = array(
     'title' => 'Translation',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       drupal_get_path('module', 'translation') . '/translation.js' => array(),
     ),
diff --git a/core/modules/translation/translation.pages.inc b/core/modules/translation/translation.pages.inc
index b5ec442cb39b65b8749b3d9b2e01bf7d01f32790..4fff31dd6bf04234f64cd9c6a72b1083168ea202 100644
--- a/core/modules/translation/translation.pages.inc
+++ b/core/modules/translation/translation.pages.inc
@@ -33,7 +33,7 @@ function translation_node_overview(EntityInterface $node) {
     $translations = array($node->language()->id => $node);
   }
 
-  $type = Drupal::config('translation.settings')->get('language_type');
+  $type = \Drupal::config('translation.settings')->get('language_type');
   $header = array(t('Language'), t('Title'), t('Status'), t('Operations'));
 
   foreach (language_list() as $langcode => $language) {
diff --git a/core/modules/update/tests/modules/update_test/update_test.module b/core/modules/update/tests/modules/update_test/update_test.module
index eef4c67b072e8452349897b334c4fd5330585d63..7898dba3d0bfb0c11c796395a49d32ee4c171e46 100644
--- a/core/modules/update/tests/modules/update_test/update_test.module
+++ b/core/modules/update/tests/modules/update_test/update_test.module
@@ -45,7 +45,7 @@ function update_test_menu() {
  * just for that module or theme.
  */
 function update_test_system_info_alter(&$info, $file) {
-  $setting = Drupal::config('update_test.settings')->get('system_info');
+  $setting = \Drupal::config('update_test.settings')->get('system_info');
   foreach (array('#all', $file->name) as $id) {
     if (!empty($setting[$id])) {
       foreach ($setting[$id] as $key => $value) {
@@ -67,7 +67,7 @@ function update_test_system_info_alter(&$info, $file) {
  * module or theme.
  */
 function update_test_update_status_alter(&$projects) {
-  $setting = Drupal::config('update_test.settings')->get('update_status');
+  $setting = \Drupal::config('update_test.settings')->get('update_status');
   if (!empty($setting)) {
     foreach ($projects as $project_name => &$project) {
       foreach (array('#all', $project_name) as $id) {
@@ -103,7 +103,7 @@ function update_test_update_status_alter(&$projects) {
  * @see update_test_menu()
  */
 function update_test_mock_page($project_name) {
-  $xml_map = Drupal::config('update_test.settings')->get('xml_map');
+  $xml_map = \Drupal::config('update_test.settings')->get('xml_map');
   if (isset($xml_map[$project_name])) {
     $availability_scenario = $xml_map[$project_name];
   }
diff --git a/core/modules/update/update.api.php b/core/modules/update/update.api.php
index ce8234c606fdf665796b24eed687cf1e75902e92..b5c81201804794070334f46f98d9a2d00f2556f5 100644
--- a/core/modules/update/update.api.php
+++ b/core/modules/update/update.api.php
@@ -83,7 +83,7 @@ function hook_update_projects_alter(&$projects) {
  * @see update_calculate_project_data()
  */
 function hook_update_status_alter(&$projects) {
-  $settings = Drupal::config('update_advanced.settings')->get('projects');
+  $settings = \Drupal::config('update_advanced.settings')->get('projects');
   foreach ($projects as $project => $project_info) {
     if (isset($settings[$project]) && isset($settings[$project]['check']) &&
         ($settings[$project]['check'] == 'never' ||
diff --git a/core/modules/update/update.authorize.inc b/core/modules/update/update.authorize.inc
index ab5f5bc59ddb505bd50259e96969e64dfbe2e0a6..9245fa181d6eed3a3f98079637d111a10e8c91fa 100644
--- a/core/modules/update/update.authorize.inc
+++ b/core/modules/update/update.authorize.inc
@@ -191,7 +191,7 @@ function update_authorize_update_batch_finished($success, $results) {
       $success = FALSE;
     }
   }
-  $offline = Drupal::state()->get('system.maintenance_mode');
+  $offline = \Drupal::state()->get('system.maintenance_mode');
   if ($success) {
     // Now that the update completed, we need to clear the available update data
     // and recompute our status, so prevent show bogus results.
@@ -199,7 +199,7 @@ function update_authorize_update_batch_finished($success, $results) {
 
     // Take the site out of maintenance mode if it was previously that way.
     if ($offline && isset($_SESSION['maintenance_mode']) && $_SESSION['maintenance_mode'] == FALSE) {
-      Drupal::state()->set('system.maintenance_mode', FALSE);
+      \Drupal::state()->set('system.maintenance_mode', FALSE);
       $page_message = array(
         'message' => t('Update was completed successfully. Your site has been taken out of maintenance mode.'),
         'type' => 'status',
@@ -258,11 +258,11 @@ function update_authorize_install_batch_finished($success, $results) {
       $success = FALSE;
     }
   }
-  $offline = Drupal::state()->get('system.maintenance_mode');
+  $offline = \Drupal::state()->get('system.maintenance_mode');
   if ($success) {
     // Take the site out of maintenance mode if it was previously that way.
     if ($offline && isset($_SESSION['maintenance_mode']) && $_SESSION['maintenance_mode'] == FALSE) {
-      Drupal::state()->set('system.maintenance_mode', FALSE);
+      \Drupal::state()->set('system.maintenance_mode', FALSE);
       $page_message = array(
         'message' => t('Installation was completed successfully. Your site has been taken out of maintenance mode.'),
         'type' => 'status',
@@ -328,6 +328,6 @@ function _update_batch_create_message(&$project_results, $message, $success = TR
  * @see update_storage_clear()
  */
 function _update_authorize_clear_update_status() {
-  Drupal::keyValueExpirable('update')->deleteAll();
-  Drupal::keyValueExpirable('update_available_release')->deleteAll();
+  \Drupal::keyValueExpirable('update')->deleteAll();
+  \Drupal::keyValueExpirable('update_available_release')->deleteAll();
 }
diff --git a/core/modules/update/update.compare.inc b/core/modules/update/update.compare.inc
index 3c0422d36741066bee1312f291f25982a000325a..15446a37d6ad92097aeb469c60a2875489d01dd2 100644
--- a/core/modules/update/update.compare.inc
+++ b/core/modules/update/update.compare.inc
@@ -66,14 +66,14 @@ function update_get_projects() {
       $project_info = new ProjectInfo();
       $project_info->processInfoList($projects, $module_data, 'module', TRUE);
       $project_info->processInfoList($projects, $theme_data, 'theme', TRUE);
-      if (Drupal::config('update.settings')->get('check.disabled_extensions')) {
+      if (\Drupal::config('update.settings')->get('check.disabled_extensions')) {
         $project_info->processInfoList($projects, $module_data, 'module', FALSE);
         $project_info->processInfoList($projects, $theme_data, 'theme', FALSE);
       }
       // Allow other modules to alter projects before fetching and comparing.
       drupal_alter('update_projects', $projects);
       // Store the site's project data for at most 1 hour.
-      Drupal::keyValueExpirable('update')->setWithExpire('update_project_projects', $projects, 3600);
+      \Drupal::keyValueExpirable('update')->setWithExpire('update_project_projects', $projects, 3600);
     }
   }
   return $projects;
@@ -178,7 +178,7 @@ function update_calculate_project_data($available) {
   drupal_alter('update_status', $projects);
 
   // Store the site's update status for at most 1 hour.
-  Drupal::keyValueExpirable('update')->setWithExpire('update_project_data', $projects, 3600);
+  \Drupal::keyValueExpirable('update')->setWithExpire('update_project_data', $projects, 3600);
   return $projects;
 }
 
@@ -611,10 +611,10 @@ function update_project_storage($key) {
     'admin/reports/updates/check',
   );
   if (in_array(current_path(), $paths)) {
-    Drupal::keyValueExpirable('update')->delete($key);
+    \Drupal::keyValueExpirable('update')->delete($key);
   }
   else {
-    $projects = Drupal::keyValueExpirable('update')->get($key);
+    $projects = \Drupal::keyValueExpirable('update')->get($key);
   }
   return $projects;
 }
diff --git a/core/modules/update/update.fetch.inc b/core/modules/update/update.fetch.inc
index e84c6913f152fc069e80cbb8e86788a2c93c8f77..6cb7cb78f29c608501db77aa0b3b9db2ce1d0969 100644
--- a/core/modules/update/update.fetch.inc
+++ b/core/modules/update/update.fetch.inc
@@ -38,7 +38,7 @@ function update_manual_status() {
  *   Reference to an array used for Batch API storage.
  */
 function update_fetch_data_batch(&$context) {
-  $queue = Drupal::queue('update_fetch_tasks');
+  $queue = \Drupal::queue('update_fetch_tasks');
   if (empty($context['sandbox']['max'])) {
     $context['finished'] = 0;
     $context['sandbox']['max'] = $queue->numberOfItems();
@@ -109,8 +109,8 @@ function update_fetch_data_finished($success, $results) {
  * Attempts to drain the queue of tasks for release history data to fetch.
  */
 function _update_fetch_data() {
-  $queue = Drupal::queue('update_fetch_tasks');
-  $end = time() + Drupal::config('update.settings')->get('fetch.timeout');
+  $queue = \Drupal::queue('update_fetch_tasks');
+  $end = time() + \Drupal::config('update.settings')->get('fetch.timeout');
   while (time() < $end && ($item = $queue->claimItem())) {
     _update_process_fetch_task($item->data);
     $queue->deleteItem($item);
@@ -131,7 +131,7 @@ function _update_fetch_data() {
  */
 function _update_process_fetch_task($project) {
   global $base_url;
-  $update_config = Drupal::config('update.settings');
+  $update_config = \Drupal::config('update.settings');
   $fail = &drupal_static(__FUNCTION__, array());
   // This can be in the middle of a long-running batch, so REQUEST_TIME won't
   // necessarily be valid.
@@ -139,7 +139,7 @@ function _update_process_fetch_task($project) {
   if (empty($fail)) {
     // If we have valid data about release history XML servers that we have
     // failed to fetch from on previous attempts, load that.
-    $fail = Drupal::keyValueExpirable('update')->get('fetch_failures');
+    $fail = \Drupal::keyValueExpirable('update')->get('fetch_failures');
   }
 
   $max_fetch_attempts = $update_config->get('fetch.max_attempts');
@@ -153,7 +153,7 @@ function _update_process_fetch_task($project) {
 
   if (empty($fail[$fetch_url_base]) || $fail[$fetch_url_base] < $max_fetch_attempts) {
     try {
-      $data = Drupal::httpClient()
+      $data = \Drupal::httpClient()
         ->get($url, array('Accept' => 'text/xml'))
         ->send()
         ->getBody(TRUE);
@@ -183,17 +183,17 @@ function _update_process_fetch_task($project) {
 
   $frequency = $update_config->get('check.interval_days');
   $available['last_fetch'] = REQUEST_TIME + $request_time_difference;
-  Drupal::keyValueExpirable('update_available_releases')->setWithExpire($project_name, $available, $request_time_difference + (60 * 60 * 24 * $frequency));
+  \Drupal::keyValueExpirable('update_available_releases')->setWithExpire($project_name, $available, $request_time_difference + (60 * 60 * 24 * $frequency));
 
   // Stash the $fail data back in the DB for the next 5 minutes.
-  Drupal::keyValueExpirable('update')->setWithExpire('fetch_failures', $fail, $request_time_difference + (60 * 5));
+  \Drupal::keyValueExpirable('update')->setWithExpire('fetch_failures', $fail, $request_time_difference + (60 * 5));
 
   // Whether this worked or not, we did just (try to) check for updates.
-  Drupal::state()->set('update.last_check', REQUEST_TIME + $request_time_difference);
+  \Drupal::state()->set('update.last_check', REQUEST_TIME + $request_time_difference);
 
   // Now that we processed the fetch task for this project, clear out the
   // record for this task so we're willing to fetch again.
-  Drupal::keyValue('update_fetch_task')->delete($project_name);
+  \Drupal::keyValue('update_fetch_task')->delete($project_name);
 
   return $success;
 }
@@ -210,15 +210,15 @@ function _update_refresh() {
   // since that data (even if it's stale) can be useful during
   // update_get_projects(); for example, to modules that implement
   // hook_system_info_alter() such as cvs_deploy.
-  Drupal::keyValueExpirable('update')->delete('update_project_projects');
-  Drupal::keyValueExpirable('update')->delete('update_project_data');
+  \Drupal::keyValueExpirable('update')->delete('update_project_projects');
+  \Drupal::keyValueExpirable('update')->delete('update_project_data');
 
   $projects = update_get_projects();
 
   // Now that we have the list of projects, we should also clear the available
   // release data, since even if we fail to fetch new data, we need to clear
   // out the stale data at this point.
-  Drupal::keyValueExpirable('update_available_releases')->deleteAll();
+  \Drupal::keyValueExpirable('update_available_releases')->deleteAll();
 
   foreach ($projects as $key => $project) {
     update_create_fetch_task($project);
@@ -245,12 +245,12 @@ function _update_refresh() {
 function _update_create_fetch_task($project) {
   $fetch_tasks = &drupal_static(__FUNCTION__, array());
   if (empty($fetch_tasks)) {
-    $fetch_tasks = Drupal::keyValue('update_fetch_task')->getAll();
+    $fetch_tasks = \Drupal::keyValue('update_fetch_task')->getAll();
   }
   if (empty($fetch_tasks[$project['name']])) {
-    $queue = Drupal::queue('update_fetch_tasks');
+    $queue = \Drupal::queue('update_fetch_tasks');
     $queue->createItem($project);
-    Drupal::keyValue('update_fetch_task')->set($project['name'], $project);
+    \Drupal::keyValue('update_fetch_task')->set($project['name'], $project);
     $fetch_tasks[$project['name']] = REQUEST_TIME;
   }
 }
@@ -277,7 +277,7 @@ function _update_create_fetch_task($project) {
 function _update_build_fetch_url($project, $site_key = '') {
   $name = $project['name'];
   $url = _update_get_fetch_url_base($project);
-  $url .= '/' . $name . '/' . Drupal::CORE_COMPATIBILITY;
+  $url .= '/' . $name . '/' . \Drupal::CORE_COMPATIBILITY;
 
   // Only append usage infomation if we have a site key and the project is
   // enabled. We do not want to record usage statistics for disabled projects.
@@ -319,7 +319,7 @@ function _update_get_fetch_url_base($project) {
     $url = $project['info']['project status url'];
   }
   else {
-    $url = Drupal::config('update.settings')->get('fetch.url');
+    $url = \Drupal::config('update.settings')->get('fetch.url');
     if (empty($url)) {
       $url = UPDATE_DEFAULT_URL;
     }
@@ -337,7 +337,7 @@ function _update_get_fetch_url_base($project) {
  * @see update_requirements()
  */
 function _update_cron_notify() {
-  $update_config = Drupal::config('update.settings');
+  $update_config = \Drupal::config('update.settings');
   module_load_install('update');
   $status = update_requirements('runtime');
   $params = array();
@@ -364,7 +364,7 @@ function _update_cron_notify() {
         // Track when the last mail was successfully sent to avoid sending
         // too many e-mails.
         if ($message['result']) {
-          Drupal::state()->set('update.last_email_notification', REQUEST_TIME);
+          \Drupal::state()->set('update.last_email_notification', REQUEST_TIME);
         }
       }
     }
diff --git a/core/modules/update/update.install b/core/modules/update/update.install
index 3037c84e00e268e6d81afadf636160d50878bb35..505b1ca4efa50fc20c0e8d7080af0af857aedca2 100644
--- a/core/modules/update/update.install
+++ b/core/modules/update/update.install
@@ -60,7 +60,7 @@ function update_requirements($phase) {
  * Implements hook_install().
  */
 function update_install() {
-  $queue = Drupal::queue('update_fetch_tasks', TRUE);
+  $queue = \Drupal::queue('update_fetch_tasks', TRUE);
   $queue->createQueue();
 }
 
@@ -72,7 +72,7 @@ function update_uninstall() {
   variable_del('update_last_check');
   variable_del('update_last_email_notification');
 
-  $queue = Drupal::queue('update_fetch_tasks');
+  $queue = \Drupal::queue('update_fetch_tasks');
   $queue->deleteQueue();
 }
 
diff --git a/core/modules/update/update.manager.inc b/core/modules/update/update.manager.inc
index a5e8652a0919ce8db96cf967a11abef9cef0d30e..a1eccb9b75c6659544f2017fbab4d22d7f93b463 100644
--- a/core/modules/update/update.manager.inc
+++ b/core/modules/update/update.manager.inc
@@ -285,7 +285,7 @@ function update_manager_update_form($form, $form_state = array(), $context) {
  */
 function theme_update_manager_update_form($variables) {
   $form = $variables['form'];
-  $last = Drupal::state()->get('update.last_check') ?: 0;
+  $last = \Drupal::state()->get('update.last_check') ?: 0;
   $update_last_check = array(
     '#theme' => 'update_last_check',
     '#last' => $last,
@@ -435,9 +435,9 @@ function update_manager_update_ready_form($form, &$form_state) {
  */
 function update_manager_update_ready_form_submit($form, &$form_state) {
   // Store maintenance_mode setting so we can restore it when done.
-  $_SESSION['maintenance_mode'] = Drupal::state()->get('system.maintenance_mode');
+  $_SESSION['maintenance_mode'] = \Drupal::state()->get('system.maintenance_mode');
   if ($form_state['values']['maintenance_mode'] == TRUE) {
-    Drupal::state()->set('system.maintenance_mode', TRUE);
+    \Drupal::state()->set('system.maintenance_mode', TRUE);
   }
 
   if (!empty($_SESSION['update_manager_update_projects'])) {
@@ -821,7 +821,7 @@ function update_manager_archive_extract($file, $directory) {
  *   are no errors, it will be an empty array.
  */
 function update_manager_archive_verify($project, $archive_file, $directory) {
-  return Drupal::moduleHandler()->invokeAll('verify_update_archive', array($project, $archive_file, $directory));
+  return \Drupal::moduleHandler()->invokeAll('verify_update_archive', array($project, $archive_file, $directory));
 }
 
 /**
diff --git a/core/modules/update/update.module b/core/modules/update/update.module
index 295476d4c53f2996316f4812ef636ed45dc89f10..0210c01377b7a31cd03911da06a264a886bc3180 100644
--- a/core/modules/update/update.module
+++ b/core/modules/update/update.module
@@ -281,10 +281,10 @@ function update_theme() {
  * Implements hook_cron().
  */
 function update_cron() {
-  $update_config = Drupal::config('update.settings');
+  $update_config = \Drupal::config('update.settings');
   $frequency = $update_config->get('check.interval_days');
   $interval = 60 * 60 * 24 * $frequency;
-  $last_check = Drupal::state()->get('update.last_check') ?: 0;
+  $last_check = \Drupal::state()->get('update.last_check') ?: 0;
   if ((REQUEST_TIME - $last_check) > $interval) {
     // If the configured update interval has elapsed, we want to invalidate
     // the data for all projects, attempt to re-fetch, and trigger any
@@ -297,7 +297,7 @@ function update_cron() {
     // missing data, and if so, try to fetch the data.
     update_get_available(TRUE);
   }
-  $last_email_notice = Drupal::state()->get('update.last_email_notification') ?: 0;
+  $last_email_notice = \Drupal::state()->get('update.last_email_notification') ?: 0;
   if ((REQUEST_TIME - $last_email_notice) > $interval) {
     // If configured time between notifications elapsed, send email about
     // updates possibly available.
@@ -388,7 +388,7 @@ function update_get_available($refresh = FALSE) {
   $needs_refresh = FALSE;
 
   // Grab whatever data we currently have.
-  $available = Drupal::keyValueExpirable('update_available_releases')->getAll();
+  $available = \Drupal::keyValueExpirable('update_available_releases')->getAll();
 
   $projects = update_get_projects();
   foreach ($projects as $key => $project) {
@@ -427,7 +427,7 @@ function update_get_available($refresh = FALSE) {
     update_fetch_data();
     // After processing the queue, we've (hopefully) got better data, so pull
     // the latest data again and use that directly.
-    $available = Drupal::keyValueExpirable('update_available_releases')->getAll();
+    $available = \Drupal::keyValueExpirable('update_available_releases')->getAll();
   }
 
   return $available;
@@ -489,7 +489,7 @@ function update_fetch_data() {
 function update_mail($key, &$message, $params) {
   $langcode = $message['langcode'];
   $language = language_load($langcode);
-  $message['subject'] .= t('New release(s) available for !site_name', array('!site_name' => Drupal::config('system.site')->get('name')), array('langcode' => $langcode));
+  $message['subject'] .= t('New release(s) available for !site_name', array('!site_name' => \Drupal::config('system.site')->get('name')), array('langcode' => $langcode));
   foreach ($params as $msg_type => $msg_reason) {
     $message['body'][] = _update_message_text($msg_type, $msg_reason, FALSE, $langcode);
   }
@@ -498,7 +498,7 @@ function update_mail($key, &$message, $params) {
     $message['body'][] = t('You can automatically install your missing updates using the Update manager:', array(), array('langcode' => $langcode)) . "\n" . url('admin/reports/updates/update', array('absolute' => TRUE, 'language' => $language));
   }
   $settings_url = url('admin/reports/updates/settings', array('absolute' => TRUE));
-  if (Drupal::config('update.settings')->get('notification.threshold') == 'all') {
+  if (\Drupal::config('update.settings')->get('notification.threshold') == 'all') {
     $message['body'][] = t('Your site is currently configured to send these emails when any updates are available. To get notified only for security updates, !url.', array('!url' => $settings_url));
   }
   else {
@@ -677,7 +677,7 @@ function update_verify_update_archive($project, $archive_file, $directory) {
     $info = drupal_parse_info_file($file->uri);
 
     // If the module or theme is incompatible with Drupal core, set an error.
-    if (empty($info['core']) || $info['core'] != Drupal::CORE_COMPATIBILITY) {
+    if (empty($info['core']) || $info['core'] != \Drupal::CORE_COMPATIBILITY) {
       $incompatible[] = !empty($info['name']) ? $info['name'] : t('Unknown');
     }
     else {
@@ -694,7 +694,7 @@ function update_verify_update_archive($project, $archive_file, $directory) {
       count($incompatible),
       '%archive_file contains a version of %names that is not compatible with Drupal !version.',
       '%archive_file contains versions of modules or themes that are not compatible with Drupal !version: %names',
-      array('!version' => Drupal::CORE_COMPATIBILITY, '%archive_file' => drupal_basename($archive_file), '%names' => implode(', ', $incompatible))
+      array('!version' => \Drupal::CORE_COMPATIBILITY, '%archive_file' => drupal_basename($archive_file), '%names' => implode(', ', $incompatible))
     );
   }
 
@@ -705,8 +705,8 @@ function update_verify_update_archive($project, $archive_file, $directory) {
  * Invalidates stored data relating to update status.
  */
 function update_storage_clear() {
-  Drupal::keyValueExpirable('update')->deleteAll();
-  Drupal::keyValueExpirable('update_available_release')->deleteAll();
+  \Drupal::keyValueExpirable('update')->deleteAll();
+  \Drupal::keyValueExpirable('update_available_release')->deleteAll();
 }
 
 /**
diff --git a/core/modules/update/update.report.inc b/core/modules/update/update.report.inc
index 1ce4f7cdcdaadd3b79f9600c851c1514e4ca77fa..4c5264e0f86442591a631d754c19fad52ea5afd2 100644
--- a/core/modules/update/update.report.inc
+++ b/core/modules/update/update.report.inc
@@ -17,7 +17,7 @@
 function theme_update_report($variables) {
   $data = $variables['data'];
 
-  $last = Drupal::state()->get('update.last_check') ?: 0;
+  $last = \Drupal::state()->get('update.last_check') ?: 0;
   $update_last_check = array(
     '#theme' => 'update_last_check',
     '#last' => $last,
@@ -32,7 +32,7 @@ function theme_update_report($variables) {
   $header = array();
   $rows = array();
 
-  $notification_level = Drupal::config('update.settings')->get('notification.threshold');
+  $notification_level = \Drupal::config('update.settings')->get('notification.threshold');
 
   // Create an array of status values keyed by module or theme name, since
   // we'll need this while generating the report if we have to cross reference
diff --git a/core/modules/user/user.api.php b/core/modules/user/user.api.php
index b7f8b8c3120577f8d90cd3ec4b0e145db71c9678..5c66c0a4c678a016973397524927488d60a015cc 100644
--- a/core/modules/user/user.api.php
+++ b/core/modules/user/user.api.php
@@ -283,7 +283,7 @@ function hook_user_update($account) {
  *   The user object on which the operation was just performed.
  */
 function hook_user_login($account) {
-  $config = Drupal::config('system.date');
+  $config = \Drupal::config('system.date');
   // If the user has a NULL time zone, notify them to set a time zone.
   if (!$account->getTimezone() && $config->get('timezone.user.configurable') && $config->get('timezone.user.warn')) {
     drupal_set_message(t('Configure your <a href="@user-edit">account time zone setting</a>.', array('@user-edit' => url("user/" . $account->id() . "/edit", array('query' => drupal_get_destination(), 'fragment' => 'edit-timezone')))));
diff --git a/core/modules/user/user.install b/core/modules/user/user.install
index 2d5b03e5d525d2289df943d50f9e7c191e13edcd..ef7d378c5e457aba3289026e67951e5433d767e7 100644
--- a/core/modules/user/user.install
+++ b/core/modules/user/user.install
@@ -495,7 +495,7 @@ function user_update_8004() {
     '2' => 'visitors_admin_approval',
   );
 
-  $config = Drupal::config('user.settings');
+  $config = \Drupal::config('user.settings');
   $user_register = $config->get('register');
   $user_cancel_method = $config->get('cancel_method');
 
@@ -1045,7 +1045,7 @@ function user_update_8018() {
     ->fetchAll();
 
   foreach ($roles as $role) {
-    Drupal::config('user.role.' . $role->rid)
+    \Drupal::config('user.role.' . $role->rid)
       ->set('id', $role->rid)
       ->set('uuid', $uuid->generate())
       ->set('label', $role->name)
@@ -1128,7 +1128,7 @@ function user_update_8020() {
     }
   }
   foreach ($new_permissions as $rid => $permissions) {
-    Drupal::config("user.role.$rid")
+    \Drupal::config("user.role.$rid")
       ->set('permissions', $permissions)
       ->save();
   }
@@ -1140,7 +1140,7 @@ function user_update_8020() {
 function user_update_8021() {
   $uuid = new Uuid();
 
-  Drupal::config("entity.form_mode.user.register")
+  \Drupal::config("entity.form_mode.user.register")
     ->set('id', "user.register")
     ->set('uuid', $uuid->generate())
     ->set('label', 'Register')
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 7037793762a5c2db31b054259f3e01467de7aab6..3bc4534f70be77b7559011b84cac6f71f4d28cd4 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -214,7 +214,7 @@ function user_field_extra_fields() {
     'description' => t('User module account form elements.'),
     'weight' => -10,
   );
-  if (Drupal::config('user.settings')->get('signatures')) {
+  if (\Drupal::config('user.settings')->get('signatures')) {
     $fields['user']['user']['form']['signature_settings'] = array(
       'label' => t('Signature settings'),
       'description' => t('User module form element.'),
@@ -226,7 +226,7 @@ function user_field_extra_fields() {
     'description' => t('User module form element.'),
     'weight' => 0,
   );
-  if (Drupal::config('system.date')->get('timezone.user.configurable')) {
+  if (\Drupal::config('system.date')->get('timezone.user.configurable')) {
     $fields['user']['user']['form']['timezone'] = array(
       'label' => t('Timezone'),
       'description' => t('System module form element.'),
@@ -418,7 +418,7 @@ function user_role_permissions(array $roles) {
 function _user_role_permissions_update($roles) {
   $role_permissions = array();
   foreach ($roles as $rid) {
-    $role_permissions[$rid] = Drupal::config("user.role.$rid")->get('permissions') ?: array();
+    $role_permissions[$rid] = \Drupal::config("user.role.$rid")->get('permissions') ?: array();
   }
   return $role_permissions;
 }
@@ -443,7 +443,7 @@ function user_access($string, AccountInterface $account = NULL) {
   if (!isset($account)) {
     // In the installer request session is not set, so we have to fall back
     // to the global $user. In all other cases the session key is preferred.
-    $account = Drupal::request()->attributes->get('_account') ?: $user;
+    $account = \Drupal::request()->attributes->get('_account') ?: $user;
   }
 
   return $account->hasPermission($string);
@@ -493,7 +493,7 @@ function user_permission() {
     ),
     'cancel account' => array(
       'title' => t('Cancel own user account'),
-      'description' => t('Note: content may be kept, unpublished, deleted or transferred to the %anonymous-name user depending on the configured <a href="@user-settings-url">user settings</a>.', array('%anonymous-name' => Drupal::config('user.settings')->get('anonymous'), '@user-settings-url' => url('admin/config/people/accounts'))),
+      'description' => t('Note: content may be kept, unpublished, deleted or transferred to the %anonymous-name user depending on the configured <a href="@user-settings-url">user settings</a>.', array('%anonymous-name' => \Drupal::config('user.settings')->get('anonymous'), '@user-settings-url' => url('admin/config/people/accounts'))),
     ),
     'select account cancellation method' => array(
       'title' => t('Select method for cancelling own account'),
@@ -539,7 +539,7 @@ function user_validate_current_pass(&$form, &$form_state) {
     // that prevent them from being empty if they are changed.
     $current_value = $account->getPropertyDefinition($key) ? $account->get($key)->value : $account->$key;
     if ((strlen(trim($form_state['values'][$key])) > 0) && ($form_state['values'][$key] != $current_value)) {
-      $current_pass_failed = empty($form_state['values']['current_pass']) || !Drupal::service('password')->check($form_state['values']['current_pass'], $account);
+      $current_pass_failed = empty($form_state['values']['current_pass']) || !\Drupal::service('password')->check($form_state['values']['current_pass'], $account);
       if ($current_pass_failed) {
         form_set_error('current_pass', t("Your current password is missing or incorrect; it's required to change the %name.", array('%name' => $name)));
         form_set_error($key);
@@ -722,7 +722,7 @@ function user_is_logged_in() {
  *   TRUE if the user is not already logged in and can register for an account.
  */
 function user_register_access() {
-  return user_is_anonymous() && (Drupal::config('user.settings')->get('register') != USER_REGISTER_ADMINISTRATORS_ONLY);
+  return user_is_anonymous() && (\Drupal::config('user.settings')->get('register') != USER_REGISTER_ADMINISTRATORS_ONLY);
 }
 
 /**
@@ -1023,7 +1023,7 @@ function user_authenticate($name, $password) {
   if (!empty($name) && !empty($password)) {
     $account = user_load_by_name($name);
     if ($account) {
-      $password_hasher = Drupal::service('password');
+      $password_hasher = \Drupal::service('password');
       if ($password_hasher->check($password, $account)) {
         // Successful authentication.
         $uid = $account->id();
@@ -1070,7 +1070,7 @@ function user_login_finalize(UserInterface $account) {
   // or incorrectly does a redirect which would leave the old session in place.
   drupal_session_regenerate();
 
-  Drupal::moduleHandler()->invokeAll('user_login', array($user));
+  \Drupal::moduleHandler()->invokeAll('user_login', array($user));
 }
 
 /**
@@ -1207,7 +1207,7 @@ function user_cancel($edit, $uid, $method) {
   // should use those hooks to respond to the account deletion.
   if ($method != 'user_cancel_delete') {
     // Allow modules to add further sets to this batch.
-    Drupal::moduleHandler()->invokeAll('user_cancel', array($edit, $account, $method));
+    \Drupal::moduleHandler()->invokeAll('user_cancel', array($edit, $account, $method));
   }
 
   // Finish the batch and actually cancel the account.
@@ -1303,7 +1303,7 @@ function _user_cancel_session_regenerate() {
  * @see user_admin_settings()
  */
 function user_cancel_methods() {
-  $user_settings = Drupal::config('user.settings');
+  $user_settings = \Drupal::config('user.settings');
   $anonymous_name = $user_settings->get('anonymous');
   $methods = array(
     'user_cancel_block' => array(
@@ -1321,11 +1321,11 @@ function user_cancel_methods() {
     'user_cancel_delete' => array(
       'title' => t('Delete the account and its content.'),
       'description' => t('Your account will be removed and all account information deleted. All of your content will also be deleted.'),
-      'access' => Drupal::request()->attributes->get('_account')->hasPermission('administer users'),
+      'access' => \Drupal::request()->attributes->get('_account')->hasPermission('administer users'),
     ),
   );
   // Allow modules to customize account cancellation methods.
-  Drupal::moduleHandler()->alter('user_cancel_methods', $methods);
+  \Drupal::moduleHandler()->alter('user_cancel_methods', $methods);
 
   // Turn all methods into real form elements.
   $form = array(
@@ -1432,7 +1432,7 @@ function user_view_multiple($accounts, $view_mode = 'full', $langcode = NULL) {
  * Implements hook_mail().
  */
 function user_mail($key, &$message, $params) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
   $langcode = $message['langcode'];
   $variables = array('user' => $params['account']);
 
@@ -1442,7 +1442,7 @@ function user_mail($key, &$message, $params) {
   // the locale module is enabled.
   $user_config_context = config_context_enter('Drupal\user\UserConfigContext');
   $user_config_context->setAccount($params['account']);
-  $mail_config = Drupal::config('user.mail');
+  $mail_config = \Drupal::config('user.mail');
 
    // We do not sanitize the token replacement, since the output of this
    // replacement is intended for an e-mail message, not a web browser.
@@ -1615,7 +1615,7 @@ function user_role_load($rid) {
  */
 function user_permission_get_modules() {
   $permissions = array();
-  foreach (Drupal::moduleHandler()->getImplementations('permission') as $module) {
+  foreach (\Drupal::moduleHandler()->getImplementations('permission') as $module) {
     $perms = module_invoke($module, 'permission');
     foreach ($perms as $key => $value) {
       $permissions[$key] = $module;
@@ -1762,17 +1762,17 @@ function theme_user_signature($variables) {
  */
 function _user_mail_notify($op, $account, $langcode = NULL) {
   // By default, we always notify except for canceled and blocked.
-  $notify = Drupal::config('user.settings')->get('notify.' . $op);
+  $notify = \Drupal::config('user.settings')->get('notify.' . $op);
   if ($notify || ($op != 'status_canceled' && $op != 'status_blocked')) {
     $params['account'] = $account;
     $langcode = $langcode ? $langcode : $account->getPreferredLangcode();
     // Get the custom site notification email to use as the from email address
     // if it has been set.
-    $site_mail = Drupal::config('system.site')->get('mail_notification');
+    $site_mail = \Drupal::config('system.site')->get('mail_notification');
     // If the custom site notification email has not been set, we use the site
     // default for this.
     if (empty($site_mail)) {
-      $site_mail = Drupal::config('system.site')->get('mail');
+      $site_mail = \Drupal::config('system.site')->get('mail');
     }
     if (empty($site_mail)) {
       $site_mail = ini_get('sendmail_from');
@@ -1804,7 +1804,7 @@ function user_form_process_password_confirm($element) {
     'showStrengthIndicator' => FALSE,
   );
 
-  if (Drupal::config('user.settings')->get('password_strength')) {
+  if (\Drupal::config('user.settings')->get('password_strength')) {
 
     global $user;
     $password_settings['showStrengthIndicator'] = TRUE;
@@ -1868,7 +1868,7 @@ function user_node_load($nodes, $types) {
  */
 function user_modules_installed($modules) {
   // Assign all available permissions to the administrator role.
-  $rid = Drupal::config('user.settings')->get('admin_role');
+  $rid = \Drupal::config('user.settings')->get('admin_role');
   if ($rid) {
     $permissions = array();
     foreach ($modules as $module) {
@@ -1887,7 +1887,7 @@ function user_modules_installed($modules) {
  */
 function user_modules_uninstalled($modules) {
   // Remove any potentially orphan module data stored for users.
-  Drupal::service('user.data')->delete($modules);
+  \Drupal::service('user.data')->delete($modules);
 }
 
 /**
@@ -2003,7 +2003,7 @@ function user_library_info() {
   $path = drupal_get_path('module', 'user');
   $libraries['drupal.user'] = array(
     'title' => 'User',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/user.js' => array(),
     ),
@@ -2019,7 +2019,7 @@ function user_library_info() {
 
   $libraries['drupal.user.permissions'] = array(
     'title' => 'User permissions',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . '/user.permissions.js' => array(),
     ),
@@ -2032,7 +2032,7 @@ function user_library_info() {
 
   $libraries['drupal.user.icons'] = array(
     'title' => 'User icon styling',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'css' => array(
       $path . '/css/user.icons.css' => array(),
     ),
@@ -2049,7 +2049,7 @@ function user_logout() {
 
   watchdog('user', 'Session closed for %name.', array('%name' => $user->getUsername()));
 
-  Drupal::moduleHandler()->invokeAll('user_logout', array($user));
+  \Drupal::moduleHandler()->invokeAll('user_logout', array($user));
 
   // Destroy the current session, and reset $user to the anonymous user.
   session_destroy();
diff --git a/core/modules/user/user.pages.inc b/core/modules/user/user.pages.inc
index a9cf4266ff3f9ae3c609efdc42c178bde9e9e168..6e4f9993e143df34228db95bd8a8db89e77e012d 100644
--- a/core/modules/user/user.pages.inc
+++ b/core/modules/user/user.pages.inc
@@ -39,7 +39,7 @@ function user_pass_reset($form, &$form_state, $uid, $timestamp, $hashed_pass, $a
   }
   else {
     // Time out, in seconds, until login URL expires.
-    $timeout = Drupal::config('user.settings')->get('password_reset_timeout');
+    $timeout = \Drupal::config('user.settings')->get('password_reset_timeout');
     $current = REQUEST_TIME;
     $account = user_load($uid);
     // Verify that the user exists and is active.
@@ -130,12 +130,12 @@ function user_cancel_confirm($account, $timestamp = 0, $hashed_pass = '') {
   $current = REQUEST_TIME;
 
   // Basic validation of arguments.
-  $account_data = Drupal::service('user.data')->get('user', $account->id());
+  $account_data = \Drupal::service('user.data')->get('user', $account->id());
   if (isset($account_data['cancel_method']) && !empty($timestamp) && !empty($hashed_pass)) {
     // Validate expiration and hashed password/login.
     if ($timestamp <= $current && $current - $timestamp < $timeout && $account->id() && $timestamp >= $account->getLastLoginTime() && $hashed_pass == user_pass_rehash($account->getPassword(), $timestamp, $account->getLastLoginTime())) {
       $edit = array(
-        'user_cancel_notify' => isset($account_data['cancel_notify']) ? $account_data['cancel_notify'] : Drupal::config('user.settings')->get('notify.status_canceled'),
+        'user_cancel_notify' => isset($account_data['cancel_notify']) ? $account_data['cancel_notify'] : \Drupal::config('user.settings')->get('notify.status_canceled'),
       );
       user_cancel($edit, $account->id(), $account_data['cancel_method']);
       // Since user_cancel() is not invoked via Form API, batch processing needs
diff --git a/core/modules/user/user.tokens.inc b/core/modules/user/user.tokens.inc
index 522dec9e008aff5eab28a6593f4806f2bbb594ff..5412a38c3e60c26fe70fffb67e31960b5e3bb6d5 100644
--- a/core/modules/user/user.tokens.inc
+++ b/core/modules/user/user.tokens.inc
@@ -63,7 +63,7 @@ function user_token_info() {
  */
 function user_tokens($type, $tokens, array $data = array(), array $options = array()) {
 
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
   $url_options = array('absolute' => TRUE);
   if (isset($options['langcode'])) {
     $url_options['language'] = language_load($options['langcode']);
diff --git a/core/modules/user/user.views.inc b/core/modules/user/user.views.inc
index 710e84b78eaa348045764e78b4b004366202eb04..f49e81298f6152d5d3ac1490c949f6b33c0b3c0d 100644
--- a/core/modules/user/user.views.inc
+++ b/core/modules/user/user.views.inc
@@ -281,7 +281,7 @@ function user_views_data() {
     ),
   );
 
-  if (Drupal::moduleHandler()->moduleExists('content_translation')) {
+  if (\Drupal::moduleHandler()->moduleExists('content_translation')) {
     $data['users']['translation_link'] = array(
       'title' => t('Translation link'),
       'help' => t('Provide a link to the translations overview for users.'),
diff --git a/core/modules/views/tests/modules/views_test_data/views_test_data.install b/core/modules/views/tests/modules/views_test_data/views_test_data.install
index f01f4102736a86d69c9bf44ffb9ed61a4230c4be..8cd7f38a3c330312eba674450664d2d828b879e7 100644
--- a/core/modules/views/tests/modules/views_test_data/views_test_data.install
+++ b/core/modules/views/tests/modules/views_test_data/views_test_data.install
@@ -9,7 +9,7 @@
  * Implements hook_schema().
  */
 function views_test_data_schema() {
-  return Drupal::state()->get('views_test_data_schema');
+  return \Drupal::state()->get('views_test_data_schema');
 }
 
 /**
@@ -31,5 +31,5 @@ function views_test_data_install() {
     'em' => 'EM',
     'marquee' => 'MARQUEE'
   );
-  Drupal::config('views.settings')->set('field_rewrite_elements', $values)->save();
+  \Drupal::config('views.settings')->set('field_rewrite_elements', $values)->save();
 }
diff --git a/core/modules/views/tests/modules/views_test_data/views_test_data.module b/core/modules/views/tests/modules/views_test_data/views_test_data.module
index e5dc45ea6652bb4a1349cea5e41bcaf54129c908..4dd8fa2e3e7a4d830071ee672042f1af1136abad 100644
--- a/core/modules/views/tests/modules/views_test_data/views_test_data.module
+++ b/core/modules/views/tests/modules/views_test_data/views_test_data.module
@@ -29,7 +29,7 @@ function views_test_data_permission() {
  * @see Drupal\views\Tests\Handler\HandlerTest
  */
 function views_test_data_handler_test_access_callback() {
-  return Drupal::config('views_test_data.tests')->get('handler_access_callback');
+  return \Drupal::config('views_test_data.tests')->get('handler_access_callback');
 }
 
 /**
@@ -48,7 +48,7 @@ function views_test_data_handler_test_access_callback_argument($argument = FALSE
   // Check the argument to be sure that access arguments are passed into the
   // callback.
   if ($argument) {
-    return Drupal::config('views_test_data.tests')->get('handler_access_callback_argument');
+    return \Drupal::config('views_test_data.tests')->get('handler_access_callback_argument');
   }
   else {
     return FALSE;
@@ -60,9 +60,9 @@ function views_test_data_handler_test_access_callback_argument($argument = FALSE
  */
 function views_test_data_preprocess_views_view_table(&$variables) {
   if ($variables['view']->storage->id() == 'test_view_render') {
-    $views_render_test = Drupal::state()->get('views_render.test');
+    $views_render_test = \Drupal::state()->get('views_render.test');
     $views_render_test++;
-    Drupal::state()->set('views_render.test', $views_render_test);
+    \Drupal::state()->set('views_render.test', $views_render_test);
   }
 }
 
diff --git a/core/modules/views/tests/modules/views_test_data/views_test_data.views.inc b/core/modules/views/tests/modules/views_test_data/views_test_data.views.inc
index ad5b23fe9b10c33bec86a6ec191678907229dd1a..4fe1fe4a5601949a560031accc222a9d0f9e01af 100644
--- a/core/modules/views/tests/modules/views_test_data/views_test_data.views.inc
+++ b/core/modules/views/tests/modules/views_test_data/views_test_data.views.inc
@@ -12,7 +12,7 @@
  * Implements hook_views_data().
  */
 function views_test_data_views_data() {
-  $state = Drupal::service('state');
+  $state = \Drupal::service('state');
   $state->set('views_hook_test_views_data', TRUE);
   // We use a state variable to keep track of how many times this function is
   // called so we can assert that calls to
@@ -30,14 +30,14 @@ function views_test_data_views_data() {
  * Implements hook_views_data_alter().
  */
 function views_test_data_views_data_alter() {
-  Drupal::state()->set('views_hook_test_views_data_alter', TRUE);
+  \Drupal::state()->set('views_hook_test_views_data_alter', TRUE);
 }
 
 /**
  * Implements hook_views_analyze().
  */
 function views_test_data_views_analyze(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_analyze', TRUE);
+  \Drupal::state()->set('views_hook_test_views_analyze', TRUE);
 
   $ret = array();
 
@@ -52,5 +52,5 @@ function views_test_data_views_analyze(ViewExecutable $view) {
  * Implements hook_views_invalidate_cache().
  */
 function views_test_data_views_invalidate_cache() {
-  Drupal::state()->set('views_hook_test_views_invalidate_cache', TRUE);
+  \Drupal::state()->set('views_hook_test_views_invalidate_cache', TRUE);
 }
diff --git a/core/modules/views/tests/modules/views_test_data/views_test_data.views_execution.inc b/core/modules/views/tests/modules/views_test_data/views_test_data.views_execution.inc
index e5a42774b06eba8b416303a72e0e61318db759a5..5e778539faaa1c70d1aa21bc540756f72a6b0404 100644
--- a/core/modules/views/tests/modules/views_test_data/views_test_data.views_execution.inc
+++ b/core/modules/views/tests/modules/views_test_data/views_test_data.views_execution.inc
@@ -12,28 +12,28 @@
  * Implements hook_views_query_substitutions().
  */
 function views_test_data_views_query_substitutions(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_query_substitutions', TRUE);
+  \Drupal::state()->set('views_hook_test_views_query_substitutions', TRUE);
 }
 
 /**
  * Implements hook_views_form_substitutions().
  */
 function views_test_data_views_form_substitutions(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_form_substitutions', TRUE);
+  \Drupal::state()->set('views_hook_test_views_form_substitutions', TRUE);
 }
 
 /**
  * Implements hook_field_views_data().
  */
 function views_test_data_field_views_data($field) {
-  Drupal::state()->set('views_hook_test_field_views_data', TRUE);
+  \Drupal::state()->set('views_hook_test_field_views_data', TRUE);
 }
 
 /**
  * Implements hook_field_views_data_alter().
  */
 function views_test_data_field_views_data_alter(&$data, $field, $module) {
-  Drupal::state()->set('views_hook_test_field_views_data_alter', TRUE);
+  \Drupal::state()->set('views_hook_test_field_views_data_alter', TRUE);
 }
 
 /**
@@ -43,7 +43,7 @@ function views_test_data_field_views_data_alter(&$data, $field, $module) {
  * @see \Drupal\views\Tests\Plugin\RenderTest
  */
 function views_test_data_views_pre_render(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_pre_render', TRUE);
+  \Drupal::state()->set('views_hook_test_views_pre_render', TRUE);
 
   if (isset($view) && ($view->storage->id() == 'test_cache_header_storage')) {
     $path = drupal_get_path('module', 'views_test_data');
@@ -58,21 +58,21 @@ function views_test_data_views_pre_render(ViewExecutable $view) {
  * Implements hook_views_post_render().
  */
 function views_test_data_views_post_render(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_post_render', TRUE);
+  \Drupal::state()->set('views_hook_test_views_post_render', TRUE);
 }
 
 /**
  * Implements hook_views_pre_build().
  */
 function views_test_data_views_pre_build(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_pre_build', TRUE);
+  \Drupal::state()->set('views_hook_test_views_pre_build', TRUE);
 }
 
 /**
  * Implements hook_views_post_build().
  */
 function views_test_data_views_post_build(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_post_build', TRUE);
+  \Drupal::state()->set('views_hook_test_views_post_build', TRUE);
 
   if (isset($view) && ($view->storage->id() == 'test_page_display')) {
     if ($view->current_display == 'page_1') {
@@ -88,26 +88,26 @@ function views_test_data_views_post_build(ViewExecutable $view) {
  * Implements hook_views_pre_view().
  */
 function views_test_data_views_pre_view(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_pre_view', TRUE);
+  \Drupal::state()->set('views_hook_test_views_pre_view', TRUE);
 }
 
 /**
  * Implements hook_views_pre_execute().
  */
 function views_test_data_views_pre_execute(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_pre_execute', TRUE);
+  \Drupal::state()->set('views_hook_test_views_pre_execute', TRUE);
 }
 
 /**
  * Implements hook_views_post_execute().
  */
 function views_test_data_views_post_execute(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_post_execute', TRUE);
+  \Drupal::state()->set('views_hook_test_views_post_execute', TRUE);
 }
 
 /**
  * Implements hook_views_query_alter().
  */
 function views_test_data_views_query_alter(ViewExecutable $view) {
-  Drupal::state()->set('views_hook_test_views_query_alter', TRUE);
+  \Drupal::state()->set('views_hook_test_views_query_alter', TRUE);
 }
diff --git a/core/modules/views/views.api.php b/core/modules/views/views.api.php
index 261c357262e0aa9a420278ea08d6b44b63329e58..ea2c97cae91af2650f09c8da4e9c0a86cf650819 100644
--- a/core/modules/views/views.api.php
+++ b/core/modules/views/views.api.php
@@ -336,7 +336,7 @@ function hook_views_data_alter(array &$data) {
 function hook_views_query_substitutions(ViewExecutable $view) {
   // Example from views_views_query_substitutions().
   return array(
-    '***CURRENT_VERSION***' => Drupal::VERSION,
+    '***CURRENT_VERSION***' => \Drupal::VERSION,
     '***CURRENT_TIME***' => REQUEST_TIME,
     '***CURRENT_LANGUAGE***' => language(\Drupal\Core\Language\Language::TYPE_CONTENT)->id,
     '***DEFAULT_LANGUAGE***' => language_default()->id,
diff --git a/core/modules/views/views.module b/core/modules/views/views.module
index 603ddf3f1304a8664e66265eaa24e8c63caac690..d8e0712361e31a3bafc23ad870ad9852ddda5019 100644
--- a/core/modules/views/views.module
+++ b/core/modules/views/views.module
@@ -84,7 +84,7 @@ function views_pre_render_view_element($element) {
  * definitions.
  */
 function views_theme($existing, $type, $theme, $path) {
-  Drupal::moduleHandler()->loadInclude('views', 'inc', 'views.theme');
+  \Drupal::moduleHandler()->loadInclude('views', 'inc', 'views.theme');
 
   // Some quasi clever array merging here.
   $base = array(
@@ -121,7 +121,7 @@ function views_theme($existing, $type, $theme, $path) {
   );
 
   $plugins = views_get_plugin_definitions();
-  $module_handler = Drupal::moduleHandler();
+  $module_handler = \Drupal::moduleHandler();
 
   // Register theme functions for all style plugins. It provides a basic auto
   // implementation of theme functions or template files by using the plugin
@@ -256,7 +256,7 @@ function views_plugin_list() {
  * node portion of the theme registry.
  */
 function views_preprocess_node(&$variables) {
-  Drupal::moduleHandler()->loadInclude('node', 'views.inc');
+  \Drupal::moduleHandler()->loadInclude('node', 'views.inc');
   // The 'view' attribute of the node is added in
   // \Drupal\views\Plugin\views\row\EntityRow::preRender().
   if (!empty($variables['node']->view) && $variables['node']->view->storage->id()) {
@@ -685,20 +685,20 @@ function views_invalidate_cache() {
   Cache::deleteTags(array('content' => TRUE));
 
   // Set the menu as needed to be rebuilt.
-  Drupal::state()->set('menu_rebuild_needed', TRUE);
+  \Drupal::state()->set('menu_rebuild_needed', TRUE);
 
-  $module_handler = Drupal::moduleHandler();
+  $module_handler = \Drupal::moduleHandler();
 
   // Set the router to be rebuild.
   // @todo Figure out why the cache rebuild is trigged but the route table
   //   does not exist yet.
   if (db_table_exists('router')) {
-    Drupal::service('router.builder')->rebuild();
+    \Drupal::service('router.builder')->rebuild();
   }
 
   // Invalidate the block cache to update views block derivatives.
   if ($module_handler->moduleExists('block')) {
-    Drupal::service('plugin.manager.block')->clearCachedDefinitions();
+    \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
   }
 
   // Allow modules to respond to the Views cache being cleared.
@@ -802,14 +802,14 @@ function views_library_info() {
   $path = drupal_get_path('module', 'views');
   $libraries['views.module'] = array(
     'title' => 'Views base',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'css' => array(
       "$path/css/views.module.css"
     ),
   );
   $libraries['views.ajax'] = array(
     'title' => 'Views AJAX',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       "$path/js/base.js" => array('group' => JS_DEFAULT),
       "$path/js/ajax_view.js" => array('group' => JS_DEFAULT),
@@ -825,7 +825,7 @@ function views_library_info() {
   );
   $libraries['views.contextual-links'] = array(
     'title' => 'Views Contextual links',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       // Set to -10 to move it before the contextual links javascript file.
       "$path/js/views-contextual.js" => array('group' => JS_LIBRARY, 'weight' => -10),
@@ -837,7 +837,7 @@ function views_library_info() {
   );
   $libraries['views.exposed-form'] = array(
     'title' => 'Views exposed form',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'css' => array(
       "$path/css/views.exposed_form.css",
     ),
@@ -902,7 +902,7 @@ function views_get_plugin_definitions() {
  * Get enabled display extenders.
  */
 function views_get_enabled_display_extenders() {
-  $enabled = array_filter((array) Drupal::config('views.settings')->get('display_extenders'));
+  $enabled = array_filter((array) \Drupal::config('views.settings')->get('display_extenders'));
 
   return drupal_map_assoc($enabled);
 }
@@ -933,13 +933,13 @@ function views_get_applicable_views($type) {
     }
   }
 
-  $entity_ids = Drupal::service('entity.query')->get('view')
+  $entity_ids = \Drupal::service('entity.query')->get('view')
     ->condition('status', TRUE)
     ->condition("display.*.display_plugin", $ids, 'IN')
     ->execute();
 
   $result = array();
-  foreach (Drupal::entityManager()->getStorageController('view')->loadMultiple($entity_ids) as $view) {
+  foreach (\Drupal::entityManager()->getStorageController('view')->loadMultiple($entity_ids) as $view) {
     // Check each display to see if it meets the criteria and is enabled.
     $executable = $view->getExecutable();
     $executable->initDisplay();
@@ -957,14 +957,14 @@ function views_get_applicable_views($type) {
  * Returns an array of all views as fully loaded $view objects.
  */
 function views_get_all_views() {
-  return Drupal::entityManager()->getStorageController('view')->loadMultiple();
+  return \Drupal::entityManager()->getStorageController('view')->loadMultiple();
 }
 
 /**
  * Returns an array of all enabled views, as fully loaded $view objects.
  */
 function views_get_enabled_views() {
-  $query = Drupal::entityQuery('view')
+  $query = \Drupal::entityQuery('view')
     ->condition('status', TRUE)
     ->execute();
 
@@ -975,7 +975,7 @@ function views_get_enabled_views() {
  * Returns an array of all disabled views, as fully loaded $view objects.
  */
 function views_get_disabled_views() {
-  $query = Drupal::entityQuery('view')
+  $query = \Drupal::entityQuery('view')
     ->condition('status', FALSE)
     ->execute();
 
@@ -1334,7 +1334,7 @@ function views_pre_render_views_form_views_form($element) {
     $replace[] = isset($element[$field_name][$row_id]) ? drupal_render($element[$field_name][$row_id]) : '';
   }
   // Add in substitutions from hook_views_form_substitutions().
-  $substitutions = Drupal::moduleHandler()->invokeAll('views_form_substitutions');
+  $substitutions = \Drupal::moduleHandler()->invokeAll('views_form_substitutions');
   foreach ($substitutions as $placeholder => $substitution) {
     $search[] = $placeholder;
     $replace[] = $substitution;
@@ -1675,7 +1675,7 @@ function views_element_validate_tags($element, &$form_state) {
  *   If TRUE, the data will be cached specific to the currently active language.
  */
 function views_cache_set($cid, $data, $use_language = FALSE) {
-  if (Drupal::config('views.settings')->get('skip_cache')) {
+  if (\Drupal::config('views.settings')->get('skip_cache')) {
     return;
   }
   if ($use_language) {
@@ -1699,7 +1699,7 @@ function views_cache_set($cid, $data, $use_language = FALSE) {
  *   The cache or FALSE on failure.
  */
 function views_cache_get($cid, $use_language = FALSE) {
-  if (Drupal::config('views.settings')->get('skip_cache')) {
+  if (\Drupal::config('views.settings')->get('skip_cache')) {
     return FALSE;
   }
   if ($use_language) {
diff --git a/core/modules/views/views.theme.inc b/core/modules/views/views.theme.inc
index 2594138079c404c868d6ba92fa5755da0f5899cd..6c0af6efaabdccfddd260f9426b671905b7bd48a 100644
--- a/core/modules/views/views.theme.inc
+++ b/core/modules/views/views.theme.inc
@@ -965,7 +965,7 @@ function template_preprocess_views_view_rss(&$variables) {
 
   $style = $view->style_plugin;
 
-  $config = Drupal::config('system.site');
+  $config = \Drupal::config('system.site');
 
   // The RSS 2.0 "spec" doesn't indicate HTML can be used in the description.
   // We strip all HTML tags, but need to prevent double encoding from properly
diff --git a/core/modules/views/views.tokens.inc b/core/modules/views/views.tokens.inc
index 91a53c6b81f04ab6a57ba774c55725a4aa2db946..bb198eb9c8d23f42ac416da87276f9b226d7059b 100644
--- a/core/modules/views/views.tokens.inc
+++ b/core/modules/views/views.tokens.inc
@@ -67,7 +67,7 @@ function views_token_info() {
  * Implements hook_tokens().
  */
 function views_tokens($type, $tokens, array $data = array(), array $options = array()) {
-  $token_service = Drupal::token();
+  $token_service = \Drupal::token();
 
   $url_options = array('absolute' => TRUE);
   if (isset($options['language'])) {
diff --git a/core/modules/views/views.views_execution.inc b/core/modules/views/views.views_execution.inc
index 73ebd09187554a7755235700e477a2530b7b04f1..e730bbb6e470cae91b610a0d2b6a42628ce798fa 100644
--- a/core/modules/views/views.views_execution.inc
+++ b/core/modules/views/views.views_execution.inc
@@ -15,7 +15,7 @@
  */
 function views_views_query_substitutions(ViewExecutable $view) {
   return array(
-    '***CURRENT_VERSION***' => Drupal::VERSION,
+    '***CURRENT_VERSION***' => \Drupal::VERSION,
     '***CURRENT_TIME***' => REQUEST_TIME,
     '***CURRENT_LANGUAGE***' => language(Language::TYPE_CONTENT)->id,
     '***DEFAULT_LANGUAGE***' => language_default()->id,
diff --git a/core/modules/views_ui/views_ui.module b/core/modules/views_ui/views_ui.module
index e684432b67d65f8824d42a5c72c5765914418b33..3d09c2cf2f75e512e529b74d719f3816fbf3f959 100644
--- a/core/modules/views_ui/views_ui.module
+++ b/core/modules/views_ui/views_ui.module
@@ -193,7 +193,7 @@ function views_ui_library_info() {
 
   $libraries['views_ui.admin'] = array(
     'title' => 'Views UI ADMIN',
-    'version' => Drupal::VERSION,
+    'version' => \Drupal::VERSION,
     'js' => array(
       $path . 'ajax.js' => array('group' => JS_DEFAULT),
       $path . 'views-admin.js' => array('group' => JS_DEFAULT),
@@ -218,7 +218,7 @@ function views_ui_library_info() {
  */
 function views_ui_preprocess_views_view(&$variables) {
   $view = $variables['view'];
-  if (!empty($view->live_preview) && Drupal::moduleHandler()->moduleExists('contextual')) {
+  if (!empty($view->live_preview) && \Drupal::moduleHandler()->moduleExists('contextual')) {
     $view->setShowAdminLinks(FALSE);
     foreach (array('title', 'header', 'exposed', 'rows', 'pager', 'more', 'footer', 'empty', 'attachment_after', 'attachment_before') as $section) {
       if (!empty($variables[$section])) {
@@ -422,7 +422,7 @@ function views_ui_views_analyze(ViewExecutable $view) {
       continue;
     }
     if ($display->hasPath() && $path = $display->getOption('path')) {
-      $normal_path = Drupal::service('path.alias_manager.cached')->getSystemPath($path);
+      $normal_path = \Drupal::service('path.alias_manager.cached')->getSystemPath($path);
       if ($path != $normal_path) {
         $ret[] = Analyzer::formatMessage(t('You have configured display %display with a path which is an path alias as well. This might lead to unwanted effects so better use an internal path.', array('%display' => $display->display['display_title'])), 'warning');
       }
diff --git a/core/modules/views_ui/views_ui.theme.inc b/core/modules/views_ui/views_ui.theme.inc
index a3e2d1b1f354ba8039ae93f24a7ee382362bdfc2..8ae5733c4868381a537766aaa799328961a7d45b 100644
--- a/core/modules/views_ui/views_ui.theme.inc
+++ b/core/modules/views_ui/views_ui.theme.inc
@@ -180,7 +180,7 @@ function theme_views_ui_build_group_filter_form($variables) {
     drupal_render($form['default_group']['All']),
     '',
     array(
-      'data' => Drupal::config('views.settings')->get('ui.exposed_filter_any_label') == 'old_any' ? t('&lt;Any&gt;') : t('- Any -'),
+      'data' => \Drupal::config('views.settings')->get('ui.exposed_filter_any_label') == 'old_any' ? t('&lt;Any&gt;') : t('- Any -'),
       'colspan' => 4,
       'class' => array('class' => 'any-default-radios-row'),
     ),
diff --git a/core/modules/xmlrpc/tests/modules/xmlrpc_test/xmlrpc_test.module b/core/modules/xmlrpc/tests/modules/xmlrpc_test/xmlrpc_test.module
index 4a772ab84593ab74a00006d7e1bd1efc569becdc..320704005369371f1bef9a0ce38f715091e65241 100644
--- a/core/modules/xmlrpc/tests/modules/xmlrpc_test/xmlrpc_test.module
+++ b/core/modules/xmlrpc/tests/modules/xmlrpc_test/xmlrpc_test.module
@@ -68,7 +68,7 @@ function xmlrpc_test_xmlrpc() {
  * Hide (or not) the system.methodSignature() service depending on a variable.
  */
 function xmlrpc_test_xmlrpc_alter(&$services) {
-  $xmlprc_alter = Drupal::state()->get('xmlrpc_test.alter') ?: FALSE;
+  $xmlprc_alter = \Drupal::state()->get('xmlrpc_test.alter') ?: FALSE;
   if ($xmlprc_alter) {
     $remove = NULL;
     foreach ($services as $key => $value) {
diff --git a/core/modules/xmlrpc/xmlrpc.inc b/core/modules/xmlrpc/xmlrpc.inc
index d529fbaafab5544e61ce8854a04741e0a61c4569..445993a1f0db7e6bd8e5a04daf09a4e60411152c 100644
--- a/core/modules/xmlrpc/xmlrpc.inc
+++ b/core/modules/xmlrpc/xmlrpc.inc
@@ -561,7 +561,7 @@ function _xmlrpc($url, array $args, array $headers = array()) {
     $args = $args[$method];
   }
   $xmlrpc_request = xmlrpc_request($method, $args);
-  $request = Drupal::httpClient()->post($url, $headers, $xmlrpc_request->xml);
+  $request = \Drupal::httpClient()->post($url, $headers, $xmlrpc_request->xml);
   $request->setHeader('Content-Type', 'text/xml');
   try {
     $response = $request->send();
diff --git a/core/modules/xmlrpc/xmlrpc.server.inc b/core/modules/xmlrpc/xmlrpc.server.inc
index b68ccbbf808db90d177cd2c73949a4263de424bb..8f171a5444a05f3cf8fff1fb4be41447df62bb80 100644
--- a/core/modules/xmlrpc/xmlrpc.server.inc
+++ b/core/modules/xmlrpc/xmlrpc.server.inc
@@ -16,7 +16,7 @@
  */
 function xmlrpc_server_page() {
   module_load_include('inc', 'xmlrpc');
-  return xmlrpc_server(Drupal::moduleHandler()->invokeAll('xmlrpc'));
+  return xmlrpc_server(\Drupal::moduleHandler()->invokeAll('xmlrpc'));
 }
 
 /**
diff --git a/core/profiles/minimal/minimal.install b/core/profiles/minimal/minimal.install
index cdc4a18db2ca91f5c659e7b7b3df4fa413d9c1cf..6f08fe7bf4fd7dc690495868f58ea0f6bd0841f7 100644
--- a/core/profiles/minimal/minimal.install
+++ b/core/profiles/minimal/minimal.install
@@ -13,10 +13,10 @@
  */
 function minimal_install() {
   // Disable the user pictures on nodes.
-  Drupal::config('system.theme.global')->set('features.node_user_picture', FALSE)->save();
+  \Drupal::config('system.theme.global')->set('features.node_user_picture', FALSE)->save();
 
   // Allow visitor account creation, but with administrative approval.
-  Drupal::config('user.settings')->set('register', USER_REGISTER_VISITORS_ADMINISTRATIVE_APPROVAL)->save();
+  \Drupal::config('user.settings')->set('register', USER_REGISTER_VISITORS_ADMINISTRATIVE_APPROVAL)->save();
 
   // Enable default permissions for system roles.
   user_role_grant_permissions(DRUPAL_ANONYMOUS_RID, array('access content'));
diff --git a/core/profiles/standard/standard.install b/core/profiles/standard/standard.install
index af30e20846bdb5e111e707bc8f1117f4e110914d..acf8871be9142b57e0993f4c2de7012796e36dbf 100644
--- a/core/profiles/standard/standard.install
+++ b/core/profiles/standard/standard.install
@@ -15,20 +15,20 @@ function standard_install() {
   // Enable Bartik theme and set it as default theme instead of Stark.
   // @see system_install()
   $default_theme = 'bartik';
-  Drupal::config('system.theme')
+  \Drupal::config('system.theme')
     ->set('default', $default_theme)
     ->save();
   theme_enable(array($default_theme));
   theme_disable(array('stark'));
 
   // Set front page to "node".
-  Drupal::config('system.site')->set('page.front', 'node')->save();
+  \Drupal::config('system.site')->set('page.front', 'node')->save();
 
   // Default "Basic page" to have comments disabled.
   variable_set('comment_page', COMMENT_NODE_HIDDEN);
 
   // Allow visitor account creation with administrative approval.
-  $user_settings = Drupal::config('user.settings');
+  $user_settings = \Drupal::config('user.settings');
   $user_settings->set('register', USER_REGISTER_VISITORS_ADMINISTRATIVE_APPROVAL)->save();
 
   // Create user picture field.
@@ -40,7 +40,7 @@ function standard_install() {
   user_role_grant_permissions(DRUPAL_AUTHENTICATED_RID, array('access content', 'access comments', 'post comments', 'skip comment approval'));
 
   // Enable all permissions for the administrator role.
-  user_role_grant_permissions('administrator', array_keys(Drupal::moduleHandler()->invokeAll('permission')));
+  user_role_grant_permissions('administrator', array_keys(\Drupal::moduleHandler()->invokeAll('permission')));
   // Set this as the administrator role.
   $user_settings->set('admin_role', 'administrator')->save();
 
@@ -84,6 +84,6 @@ function standard_install() {
 
   // Enable the admin theme.
   theme_enable(array('seven'));
-  Drupal::config('system.theme')->set('admin', 'seven')->save();
-  Drupal::config('node.settings')->set('use_admin_theme', '1')->save();
+  \Drupal::config('system.theme')->set('admin', 'seven')->save();
+  \Drupal::config('node.settings')->set('use_admin_theme', '1')->save();
 }
diff --git a/core/update.php b/core/update.php
index 7ae8dd5fa93d92b555291f57eae80c653a7b0201..db92c1aa680a14ea0b227c1692b38e47ee2aa5b2 100644
--- a/core/update.php
+++ b/core/update.php
@@ -189,7 +189,7 @@ function update_helpful_links() {
  */
 function update_flush_all_caches() {
   unset($GLOBALS['conf']['container_service_providers']['UpdateServiceProvider']);
-  Drupal::service('kernel')->updateModules(Drupal::moduleHandler()->getModuleList());
+  \Drupal::service('kernel')->updateModules(\Drupal::moduleHandler()->getModuleList());
 
   // No updates to run, so caches won't get flushed later.  Clear them now.
   drupal_flush_all_caches();
@@ -351,7 +351,7 @@ function update_access_allowed() {
   // Calls to user_access() might fail during the Drupal 6 to 7 update process,
   // so we fall back on requiring that the user be logged in as user #1.
   try {
-    $module_handler = Drupal::moduleHandler();
+    $module_handler = \Drupal::moduleHandler();
     $module_filenames = $module_handler->getModuleList();
     $module_filenames['user'] = 'core/modules/user/user.module';
     $module_handler->setModuleList($module_filenames);
@@ -407,7 +407,7 @@ function update_extra_requirements($requirements = NULL) {
  */
 function update_check_requirements($skip_warnings = FALSE) {
   // Check requirements of all loaded modules.
-  $requirements = Drupal::moduleHandler()->invokeAll('requirements', array('update'));
+  $requirements = \Drupal::moduleHandler()->invokeAll('requirements', array('update'));
   $requirements += update_extra_requirements();
   $severity = drupal_requirements_severity($requirements);
 
@@ -454,11 +454,11 @@ function update_check_requirements($skip_warnings = FALSE) {
 
 // A request object from the HTTPFoundation to tell us about the request.
 $request = Request::createFromGlobals();
-Drupal::getContainer()->set('request', $request);
+\Drupal::getContainer()->set('request', $request);
 
 // Ensure that URLs generated for the home and admin pages don't have 'update.php'
 // in them.
-$generator = Drupal::urlGenerator();
+$generator = \Drupal::urlGenerator();
 $generator->setBasePath(str_replace('/core', '', $request->getBasePath()) . '/');
 $generator->setScriptPath('');