Remove unnecessary files.

core/modules/system/lib/Drupal/system/FileDownload.php

-<?php
-
-namespace Drupal\system;
-
-use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
-
-/**
- * Controller class for private file downloads.
- */
-class FileDownload {
-
-  /**
-  * Page callback: Handles private file transfers.
-  *
-  * Call modules that implement hook_file_download() to find out if a file is
-  * accessible and what headers it should be transferred with. If one or more
-  * modules returned headers the download will start with the returned headers.
-  * If a module returns -1 an AccessDeniedHttpException will be thrown.
-  * If the file exists but no modules responded an AccessDeniedHttpException will
-  * be thrown.If the file does not exist a NotFoundHttpException will be thrown.
-  *
-  * @see hook_file_download()
-  */
-  public function download() {
-    // Merge remaining path arguments into relative file path.
-    $args = func_get_args();
-    $scheme = array_shift($args);
-    $target = implode('/', $args);
-    $uri = $scheme . '://' . $target;
-    if (file_stream_wrapper_valid_scheme($scheme) && file_exists($uri)) {
-      // Let other modules provide headers and controls access to the file.
-      // module_invoke_all() uses array_merge_recursive() which merges header
-      // values into a new array. To avoid that and allow modules to override
-      // headers instead, use array_merge() to merge the returned arrays.
-      $headers = array();
-      foreach (module_implements('file_download') as $module) {
-        $function = $module . '_file_download';
-        $result = $function($uri);
-        if ($result == -1) {
-          throw new AccessDeniedHttpException();
-        }
-        if (isset($result) && is_array($result)) {
-          $headers = array_merge($headers, $result);
-        }
-      }
-      if (count($headers)) {
-        return file_transfer($uri, $headers);
-      }
-      throw new AccessDeniedHttpException();
-    }
-    throw new NotFoundHttpException();
-  }
-}

Routing @ a05bcaaa

-Subproject commit a05bcaaaa43025037a0667e158aed9b65a147e80