Add support for switching the audio output device for HTMLMediaElements.

media/audio/audio_output_stream_sink.cc

 // Copyright 2014 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.
 
 #include "media/audio/audio_output_stream_sink.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "media/audio/audio_manager.h"
@@ skipping 39 matching lines @@
   base::AutoLock al(callback_lock_);
   active_render_callback_ = render_callback_;
   audio_task_runner_->PostTask(
       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoPlay, this));
 }
 
 bool AudioOutputStreamSink::SetVolume(double volume) {
   audio_task_runner_->PostTask(
       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoSetVolume, this, volume));
   return true;
-};
+}
+
+void AudioOutputStreamSink::SwitchOutputDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const base::Callback<void(int)>& callback) { }

[miu, 2015/06/03 21:01:01]

All the other default method implementations run their callback.  You should
always run the callback passed in here with some kind of failure code.

+
 
 int AudioOutputStreamSink::OnMoreData(AudioBus* dest,
                                       uint32 total_bytes_delay) {
   // Note: Runs on the audio thread created by the OS.
   base::AutoLock al(callback_lock_);
   if (!active_render_callback_)
     return 0;
 
   return active_render_callback_->Render(
       dest, total_bytes_delay * 1000.0 / params_.GetBytesPerSecond());
@@ skipping 46 matching lines @@
   DCHECK(audio_task_runner_->BelongsToCurrentThread());
   stream_->SetVolume(volume);
 }
 
 void AudioOutputStreamSink::ClearCallback() {
   base::AutoLock al(callback_lock_);
   active_render_callback_ = NULL;
 }
 
 }  // namepace media