Add support for switching the audio output device for HTMLMediaElements.

media/renderers/audio_renderer_impl.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.
 
 // Audio rendering unit utilizing an AudioRendererSink to output data.
 //
 // This class lives inside three threads during it's lifetime, namely:
 // 1. Render thread
 //    Where the object is created.
 // 2. Media thread (provided via constructor)
 //    All AudioDecoder methods are called on this thread.
 // 3. Audio thread created by the AudioRendererSink.
 //    Render() is called here where audio data is decoded into raw PCM data.
 //
 // AudioRendererImpl talks to an AudioRendererAlgorithm that takes care of
 // queueing audio data and stretching/shrinking audio data when playback rate !=
 // 1.0 or 0.0.
 
 #ifndef MEDIA_RENDERERS_AUDIO_RENDERER_IMPL_H_
 #define MEDIA_RENDERERS_AUDIO_RENDERER_IMPL_H_
 
 #include <deque>
+#include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "media/base/audio_decoder.h"
 #include "media/base/audio_renderer.h"
 #include "media/base/audio_renderer_sink.h"
 #include "media/base/decryptor.h"
 #include "media/base/media_log.h"
@@ skipping 48 matching lines @@
                   const SetDecryptorReadyCB& set_decryptor_ready_cb,
                   const StatisticsCB& statistics_cb,
                   const BufferingStateCB& buffering_state_cb,
                   const base::Closure& ended_cb,
                   const PipelineStatusCB& error_cb,
                   const base::Closure& waiting_for_decryption_key_cb) override;
   TimeSource* GetTimeSource() override;
   void Flush(const base::Closure& callback) override;
   void StartPlaying() override;
   void SetVolume(float volume) override;
+  void SwitchOutputDevice(const std::string& device_id,
+                          const GURL& security_origin,
+                          const base::Callback<void(int)>& callback) override;
 
  private:
   friend class AudioRendererImplTest;
 
   // Important detail: being in kPlaying doesn't imply that audio is being
   // rendered. Rather, it means that the renderer is ready to go. The actual
   // rendering of audio is controlled via Start/StopRendering().
   //
   //   kUninitialized
   //         | Initialize()
@@ skipping 163 matching lines @@
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<AudioRendererImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_RENDERERS_AUDIO_RENDERER_IMPL_H_