Use the browser UI thread for audio on OSX.

chrome/browser/notifications/notification_audio_controller_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 "chrome/browser/notifications/notification_audio_controller.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/run_loop.h"
@@ skipping 22 matching lines @@
 class NotificationAudioControllerTest : public testing::Test {
  public:
   NotificationAudioControllerTest() {
     audio_manager_.reset(media::AudioManager::Create());
     notification_audio_controller_ = new NotificationAudioController();
     notification_audio_controller_->UseFakeAudioOutputForTest();
   }
 
   virtual ~NotificationAudioControllerTest() {
     notification_audio_controller_->RequestShutdown();
+    base::RunLoop run_loop;
+    run_loop.RunUntilIdle();
     audio_manager_.reset();
   }
 
  protected:
   NotificationAudioController* notification_audio_controller() {
     return notification_audio_controller_;
   }
   Profile* profile() { return &profile_; }
 
   size_t GetHandlersSize() {
@@ skipping 64 matching lines @@
   notification_audio_controller()->RequestPlayNotificationSound(
       kDummyNotificationId,
       profile(),
       base::StringPiece(kTestAudioData, arraysize(kTestAudioData)));
   notification_audio_controller()->RequestPlayNotificationSound(
       kDummyNotificationId,
       &profile2,
       base::StringPiece(kTestAudioData, arraysize(kTestAudioData)));
   EXPECT_EQ(2u, GetHandlersSize());
 }