Replace AudioManager::Init() with InitializeOnAudioThread().

media/audio/audio_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.
 
 #ifndef MEDIA_AUDIO_AUDIO_MANAGER_H_
 #define MEDIA_AUDIO_AUDIO_MANAGER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 109 matching lines @@
     virtual void OnDeviceChange() = 0;
   };
 
   virtual void AddOutputDeviceChangeListener(AudioDeviceListener* listener) = 0;
   virtual void RemoveOutputDeviceChangeListener(
       AudioDeviceListener* listener) = 0;
 
  protected:
   AudioManager();
 
-  // Called from Create() to initialize the instance.
-  virtual void Init() = 0;
-
  private:
   DISALLOW_COPY_AND_ASSIGN(AudioManager);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_H_