Test file errors in downloads.

content/browser/download/download_file_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // The DownloadFileManager owns a set of DownloadFile objects, each of which
 // represent one in progress download and performs the disk IO for that
 // download. The DownloadFileManager itself is a singleton object owned by the
 // ResourceDispatcherHost.
 //
 // The DownloadFileManager uses the file_thread for performing file write
@@ skipping 130 matching lines @@
   // The number of downloads currently active on the DownloadFileManager.
   // Primarily for testing.
   int NumberOfActiveDownloads() const {
     return downloads_.size();
   }
 
  private:
   friend class base::RefCountedThreadSafe<DownloadFileManager>;
   friend class DownloadFileManagerTest;
   friend class DownloadManagerTest;
+  friend class TestFileErrorInjectorImpl;
   FRIEND_TEST_ALL_PREFIXES(DownloadManagerTest, StartDownload);
 
   ~DownloadFileManager();
 
+  // This is only for unit tests.
+  void SetFileFactory(DownloadFileFactory* file_factory) {
+    download_file_factory_.reset(file_factory);
+  }
+
   // Timer helpers for updating the UI about the current progress of a download.
   void StartUpdateTimer();
   void StopUpdateTimer();
   void UpdateInProgressDownloads();
 
   // Clean up helper that runs on the download thread.
   void OnShutdown();
 
   // Creates DownloadFile on FILE thread and continues starting the download
   // process.
@@ skipping 26 matching lines @@
   // is controlled from the FILE thread, and posts updates to the UI thread.
   base::RepeatingTimer<DownloadFileManager> update_timer_;
 
   ResourceDispatcherHost* resource_dispatcher_host_;
   scoped_ptr<DownloadFileFactory> download_file_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileManager);
 };
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_