Add support for switching the audio output device for HTMLMediaElements.

media/base/pipeline.cc

 // 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.
 
 #include "media/base/pipeline.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 141 matching lines @@
   base::AutoLock auto_lock(lock_);
   volume_ = volume;
   if (running_) {
     task_runner_->PostTask(
         FROM_HERE,
         base::Bind(
             &Pipeline::VolumeChangedTask, weak_factory_.GetWeakPtr(), volume));
   }
 }
 
+void Pipeline::SwitchAudioOutputDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const base::Callback<void(int)>& callback) {
+  DVLOG(1) << __FUNCTION__;
+  base::AutoLock auto_lock(lock_);
+  if (running_) {
+    task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&Pipeline::AudioOutputDeviceSwitchedTask,
+                   weak_factory_.GetWeakPtr(),
+                   device_id,
+                   security_origin,
+                   callback));
+  }
+}
+
 TimeDelta Pipeline::GetMediaTime() const {
   base::AutoLock auto_lock(lock_);
   return renderer_ ? std::min(renderer_->GetMediaTime(), duration_)
                    : TimeDelta();
 }
 
 Ranges<TimeDelta> Pipeline::GetBufferedTimeRanges() const {
   base::AutoLock auto_lock(lock_);
   return buffered_time_ranges_;
 }
@@ skipping 393 matching lines @@
 void Pipeline::VolumeChangedTask(float volume) {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   // Volume changes are only carried out while playing.
   if (state_ != kPlaying)
     return;
 
   renderer_->SetVolume(volume);
 }
 
+void Pipeline::AudioOutputDeviceSwitchedTask(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const base::Callback<void(int)>& callback) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  DVLOG(1) << __FUNCTION__ << "(" << device_id << ", "
+           << security_origin << ")";
+
+  // TODO(guidou): Check if there are any values of state_ for which switching

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

Please do this in the current CL, or submit a crbug and note the bug number
here.

+  // audio output device makes no sense.
+  renderer_->SwitchAudioOutputDevice(device_id, security_origin, callback);
+}
+
 void Pipeline::SeekTask(TimeDelta time, const PipelineStatusCB& seek_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(stop_cb_.is_null());
 
   // Suppress seeking if we're not fully started.
   if (state_ != kPlaying) {
     DCHECK(state_ == kStopping || state_ == kStopped)
         << "Receive extra seek in unexpected state: " << state_;
 
     // TODO(scherkus): should we run the callback?  I'm tempted to say the API
@@ skipping 147 matching lines @@
   metadata_cb_.Run(metadata);
 }
 
 void Pipeline::BufferingStateChanged(BufferingState new_buffering_state) {
   DVLOG(1) << __FUNCTION__ << "(" << new_buffering_state << ") ";
   DCHECK(task_runner_->BelongsToCurrentThread());
   buffering_state_cb_.Run(new_buffering_state);
 }
 
 }  // namespace media