Small refactor to media architecture in order to allow end-to-end tests.

media/audio/audio_manager.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.
 
 #include "media/audio/audio_manager.h"
 
 #include "base/at_exit.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 
 namespace media {
 
+AudioManager* AudioManager::audio_manager_for_tests_ = NULL;
+
 // Forward declaration of the platform specific AudioManager factory function.
 AudioManager* CreateAudioManager();
 
 AudioManager::AudioManager() {
 }
 
 AudioManager::~AudioManager() {
 }
 
 // static
 AudioManager* AudioManager::Create() {
+  if (audio_manager_for_tests_)
+    return audio_manager_for_tests_;
   AudioManager* ret = CreateAudioManager();
   ret->Init();
   return ret;
 }
 
+// static
+void AudioManager::set_audio_manager_for_tests(AudioManager* audio_manager) {
+  audio_manager_for_tests_ = audio_manager;
+}
+
 }  // namespace media