Add support for switching the audio output device for HTMLMediaElements.

media/base/audio_renderer_mixer.cc

Index: media/base/audio_renderer_mixer.cc
diff --git a/media/base/audio_renderer_mixer.cc b/media/base/audio_renderer_mixer.cc
index 112d7ef8b7726ad4ecf379a99d58193ff761f0dd..e91c6830d5b6144d0fec1bf8a901d25254899e3c 100644
--- a/media/base/audio_renderer_mixer.cc
+++ b/media/base/audio_renderer_mixer.cc
@@ -71,6 +71,17 @@ void AudioRendererMixer::RemoveErrorCallback(const base::Closure& error_cb) {
   NOTREACHED();
 }
 
+void AudioRendererMixer::SwitchOutputDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const base::Callback<void(int)>& callback) {
+  DVLOG(1) << __FUNCTION__ << "(" << device_id << ", "
+           << security_origin << ")";
+  base::AutoLock auto_lock(lock_);
+  audio_sink_->SwitchOutputDevice(device_id, security_origin, callback);
+}
+
+
 int AudioRendererMixer::Render(AudioBus* audio_bus,
                                int audio_delay_milliseconds) {
   base::AutoLock auto_lock(lock_);