Add support for switching the audio output device for HTMLMediaElements.

media/renderers/audio_renderer_impl.h

Index: media/renderers/audio_renderer_impl.h
diff --git a/media/renderers/audio_renderer_impl.h b/media/renderers/audio_renderer_impl.h
index 0f55f09dc88e9a6b997da74443a4ff718157d391..205c21bb548a4f58abde04ae77c85225accdd3b9 100644
--- a/media/renderers/audio_renderer_impl.h
+++ b/media/renderers/audio_renderer_impl.h
@@ -20,6 +20,7 @@
 #define MEDIA_RENDERERS_AUDIO_RENDERER_IMPL_H_
 
 #include <deque>
+#include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
@@ -88,6 +89,9 @@ class MEDIA_EXPORT AudioRendererImpl
   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;