Media Galleries API: Fix MediaGalleriesPreferences finders race.

chrome/browser/media_galleries/media_file_system_registry_unittest.cc

 // 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.
 
 // MediaFileSystemRegistry unit tests.
 
 #include <algorithm>
 #include <set>
 
 #include "base/bind_helpers.h"
@@ skipping 456 matching lines @@
   // delete everything that references the profile.
   single_web_contents_.reset();
   shared_web_contents1_.reset();
   shared_web_contents2_.reset();
   profile_.reset();
 
   base::MessageLoop::current()->RunUntilIdle();
 }
 
 MediaGalleriesPreferences* ProfileState::GetMediaGalleriesPrefs() {
-  return MediaGalleriesPreferencesFactory::GetForProfile(profile_.get());
+  MediaGalleriesPreferences* prefs =
+      MediaGalleriesPreferencesFactory::GetForProfile(profile_.get());
+  base::RunLoop loop;
+  prefs->EnsureInitialized(loop.QuitClosure());
+  loop.Run();
+  return prefs;
 }
 
 void ProfileState::CheckGalleries(
     const std::string& test,
     const std::vector<MediaFileSystemInfo>& regular_extension_galleries,
     const std::vector<MediaFileSystemInfo>& all_extension_galleries) {
   content::RenderViewHost* rvh = single_web_contents_->GetRenderViewHost();
   MediaFileSystemRegistry* registry =
       g_browser_process->media_file_system_registry();
 
@@ skipping 117 matching lines @@
     profile_states_.push_back(state);
   }
 }
 
 ProfileState* MediaFileSystemRegistryTest::GetProfileState(size_t i) {
   return profile_states_[i];
 }
 
 MediaGalleriesPreferences* MediaFileSystemRegistryTest::GetPreferences(
     Profile* profile) {
-  return registry()->GetPreferences(profile);
+  MediaGalleriesPreferences* prefs = registry()->GetPreferences(profile);
+  base::RunLoop loop;
+  prefs->EnsureInitialized(loop.QuitClosure());
+  loop.Run();
+  return prefs;
 }
 
 std::string MediaFileSystemRegistryTest::AddUserGallery(
     StorageInfo::Type type,
     const std::string& unique_id,
     const base::FilePath& path) {
   std::string device_id = StorageInfo::MakeDeviceId(type, unique_id);
   DCHECK(!StorageInfo::IsMediaDevice(device_id));
 
   for (size_t i = 0; i < profile_states_.size(); ++i) {
@@ skipping 428 matching lines @@
     profile_state->AddNameForAllCompare(path.BaseName().LossyDisplayName());
 #else
     profile_state->AddNameForAllCompare(path.LossyDisplayName());
 #endif
 
     profile_state->CheckGalleries("names-dir", one_expectation, auto_galleries);
   } else {
     profile_state->CheckGalleries("names", one_expectation, one_expectation);
   }
 }