ConfigEntity was moved to a Core component.

lib/Drupal/views/ViewStorage.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\views;
 
-use Drupal\config\ConfigEntityBase;
+use Drupal\Core\Config\Entity\ConfigEntityBase;
 
 /**
  * Defines a ViewStorage configuration entity class.

lib/Drupal/views/ViewStorageController.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\views;
 
-use Drupal\config\ConfigStorageController;
+use Drupal\Core\Config\Entity\ConfigStorageController;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Component\Uuid\Uuid;
 

lib/Drupal/views/ViewStorageInterface.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\views;
 
-use Drupal\config\ConfigEntityInterface;
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
 
 /**
  * Defines an interface for View storage classes.