Add IPC interface for switching the audio output device for a given audio stream in the browser.

media/audio/audio_logging.h

 // 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.
 
 #ifndef MEDIA_AUDIO_AUDIO_LOGGING_H_
 #define MEDIA_AUDIO_AUDIO_LOGGING_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 25 matching lines @@
 
   // Called when an audio component is closed, generally this is synonymous
   // with "deleted."
   virtual void OnClosed(int component_id) = 0;
 
   // Called when an audio component encounters an error.
   virtual void OnError(int component_id) = 0;
 
   // Called when an audio component changes volume.  |volume| is the new volume.
   virtual void OnSetVolume(int component_id, double volume) = 0;
+
+  // Called when an audio component switches output device. |device_id| is the
+  // new audio output device.
+  virtual void OnSwitchOutputDevice(int component_id,
+                                    const std::string& device_id) = 0;
 };
 
 // AudioLogFactory dispenses AudioLog instances to owning classes for tracking
 // AudioComponent behavior.  All AudioComponents have the concept of an owning
 // class:
 //
 //    - AudioInputRendererHost for AudioInputController
 //    - AudioRendererHost for AudioOutputController
 //    - AudioOutputDispatcherImpl for AudioOutputStream
 //
@@ skipping 17 matching lines @@
   // create its own AudioLog.
   virtual scoped_ptr<AudioLog> CreateAudioLog(AudioComponent component) = 0;
 
  protected:
   virtual ~AudioLogFactory() {}
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_LOGGING_H_