Add support for switching the audio output device for HTMLMediaElements.

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 814a93267dab762d04e201e7a55375ecb9d4180d..b9af114bb315f657b4d297efd62c5b3475153d12 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -370,6 +370,49 @@ void WebMediaPlayerImpl::setVolume(double volume) {
   pipeline_.SetVolume(volume);
 }
 
+void WebMediaPlayerImpl::FinishSetAudioOutputRequest(
+    blink::WebSetAudioOutputDeviceRequest *request,
+    int result) {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  DVLOG(1) << __PRETTY_FUNCTION__;
+  request->finish(result);
+  delete request;
+}
+
+void WebMediaPlayerImpl::PrepareFinishSetAudioOutputRequest(
+    WebMediaPlayerImpl* media_player,
+    const scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    blink::WebSetAudioOutputDeviceRequest *request,
+    int result) {
+  DCHECK(!task_runner->BelongsToCurrentThread());
+  DVLOG(1) << __PRETTY_FUNCTION__;
+  // TODO(guidou): Change base::Unretained to a weak pointer

[miu, 2015/06/03 21:01:02]

This TODO needs to be resolved before committing.  Also, is the base::Unretained
in the setAudioOutputDevice() method correct?.

+  task_runner->PostTask(
+      FROM_HERE, base::Bind(&WebMediaPlayerImpl::FinishSetAudioOutputRequest,
+                            base::Unretained(media_player),
+                            request,
+                            result));
+}
+
+void WebMediaPlayerImpl::setAudioOutputDevice(
+    const blink::WebSetAudioOutputDeviceRequest& request) {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  std::string device_id_str(request.deviceID().utf8());
+  GURL security_origin(request.securityOrigin().toString().utf8());
+  DVLOG(1) << __FUNCTION__ << "(" << device_id_str << ", "
+           << security_origin << ")";
+
+  blink::WebSetAudioOutputDeviceRequest *request_ptr =
+      new blink::WebSetAudioOutputDeviceRequest(request);
+  pipeline_.SwitchAudioOutputDevice(
+      device_id_str,
+      security_origin,
+      base::Bind(&WebMediaPlayerImpl::PrepareFinishSetAudioOutputRequest,
+                 base::Unretained(this),
+                 main_task_runner_,
+                 request_ptr));
+}
+
 #define STATIC_ASSERT_MATCHING_ENUM(webkit_name, chromium_name) \
     static_assert(static_cast<int>(WebMediaPlayer::webkit_name) == \
                   static_cast<int>(BufferedDataSource::chromium_name), \