Media Galleries API: Fix MediaGalleriesPreferences finders race.

chrome/browser/media_galleries/win/mtp_device_delegate_impl_win_unittest.cc

 // Copyright 2013 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.
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
@@ skipping 46 matching lines @@
   void CheckGalleryInfo(const MediaFileSystemInfo& info,
                         const string16& name,
                         const base::FilePath& path,
                         bool removable,
                         bool media_device);
 
   // Pointer to the storage monitor. Owned by TestingBrowserProcess.
   TestStorageMonitorWin* monitor_;
   scoped_refptr<extensions::Extension> extension_;
 
-  EnsureMediaDirectoriesExists media_directories_;
+  TestMediaDirectoriesOverrides media_directories_;
 };
 
 void MTPDeviceDelegateImplWinTest::SetUp() {
   ChromeRenderViewHostTestHarness::SetUp();
 
   TestStorageMonitor::RemoveSingleton();
   TestPortableDeviceWatcherWin* portable_device_watcher =
       new TestPortableDeviceWatcherWin;
   TestVolumeMountWatcherWin* mount_watcher = new TestVolumeMountWatcherWin;
   portable_device_watcher->set_use_dummy_mtp_storage_info(true);
@@ skipping 86 matching lines @@
   for (FSInfoMap::iterator i = results.begin(); i != results.end(); ++i) {
     MediaFileSystemInfo info = i->second;
     if (info.path == location) {
       CheckGalleryInfo(info, location.LossyDisplayName(), location, true, true);
       checked = true;
       break;
     }
   }
   EXPECT_TRUE(checked);
 }