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 126 matching lines @@
   void RenameCompletingDownloadFile(content::DownloadId id,
                                     const FilePath& full_path,
                                     bool overwrite_existing_file);
 
   // The number of downloads currently active on the DownloadFileManager.
   // Primarily for testing.
   int NumberOfActiveDownloads() const {
     return downloads_.size();
   }
 
+  void SetFileFactoryForTesting(scoped_ptr<DownloadFileFactory> file_factory) {
+    download_file_factory_.swap(file_factory);

[cbentzel, 2012/03/01 15:44:20]

What are you trying to do with the swap here (as opposed to reset?)

[ahendrickson, 2012/03/01 20:19:31]

This effectively does the same thing as

download_file_factory_.reset(file_factory.release());

swap() method:  file_factory will destroy the old pointer when it goes out of
scope.

reset() method:  the old pointer is destroyed when by reset(), and file_factory
becomes NULL.

I can use the reset() method if you't prefer.

[cbentzel, 2012/03/01 22:32:00]

OK, normally when I see swap I expect there to be a transfer of ownership. In
this case, the ownership would transfer but then file_factory will go out of
scope in this block. This is fine. Maybe you could use Pass here?

[ahendrickson, 2012/03/02 21:58:47]

Went the reset() way.

+  }
+
+  DownloadFileFactory* GetFileFactoryForTesting() const {
+    return download_file_factory_.get();  // Explicitly NOT a scoped_ptr.
+  }
+
  private:
   friend class base::RefCountedThreadSafe<DownloadFileManager>;
   friend class DownloadFileManagerTest;
   friend class DownloadManagerTest;
   FRIEND_TEST_ALL_PREFIXES(DownloadManagerTest, StartDownload);
 
   ~DownloadFileManager();
 
   // Timer helpers for updating the UI about the current progress of a download.
   void StartUpdateTimer();
@@ skipping 34 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_