Add support for switching the audio output device for HTMLMediaElements.

media/base/fake_audio_renderer_sink.h

Index: media/base/fake_audio_renderer_sink.h
diff --git a/media/base/fake_audio_renderer_sink.h b/media/base/fake_audio_renderer_sink.h
index c3c313ae531c83b0ab793ac6cb24ab90b2a52e06..86a708d8997cacac402d0793267d6d234b78486e 100644
--- a/media/base/fake_audio_renderer_sink.h
+++ b/media/base/fake_audio_renderer_sink.h
@@ -5,8 +5,11 @@
 #ifndef MEDIA_BASE_FAKE_AUDIO_RENDERER_SINK_H_
 #define MEDIA_BASE_FAKE_AUDIO_RENDERER_SINK_H_
 
+#include <string>
+
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_renderer_sink.h"
+#include "url/gurl.h"
 
 namespace media {
 
@@ -30,6 +33,10 @@ class FakeAudioRendererSink : public AudioRendererSink {
   void Pause() override;
   void Play() override;
   bool SetVolume(double volume) override;
+  void SwitchOutputDevice(const std::string& device_id,
+                          const GURL& security_origin,
+                          const base::Callback<void(int)>& callback) override;
+
 
   // Attempts to call Render() on the callback provided to
   // Initialize() with |dest| and |audio_delay_milliseconds|.