Add support for switching the audio output device for HTMLMediaElements.

content/renderer/media/audio_message_filter.cc

Index: content/renderer/media/audio_message_filter.cc
diff --git a/content/renderer/media/audio_message_filter.cc b/content/renderer/media/audio_message_filter.cc
index ce26c13b40c40095cfeceb24998df915db68168e..8f62083f9651effb1278d392f91d45e9179bfb04 100644
--- a/content/renderer/media/audio_message_filter.cc
+++ b/content/renderer/media/audio_message_filter.cc
@@ -4,6 +4,8 @@
 
 #include "content/renderer/media/audio_message_filter.h"
 
+#include <string>
+
 #include "base/bind.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/strings/stringprintf.h"
@@ -33,6 +35,10 @@ class AudioMessageFilter::AudioOutputIPCImpl
   void PauseStream() override;
   void CloseStream() override;
   void SetVolume(double volume) override;
+  void SwitchDevice(const std::string& device_id,
+                    const GURL& security_origin,
+                    int request_id,
+                    const base::Callback<void(int)>& callback) override;
 
  private:
   const scoped_refptr<AudioMessageFilter> filter_;
@@ -111,6 +117,21 @@ void AudioMessageFilter::AudioOutputIPCImpl::SetVolume(double volume) {
   filter_->Send(new AudioHostMsg_SetVolume(stream_id_, volume));
 }
 
+void AudioMessageFilter::AudioOutputIPCImpl::SwitchDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    int request_id,
+    const base::Callback<void(int)>& callback) {
+  DCHECK_NE(stream_id_, kStreamIDNotSet);
+  DVLOG(1) << __FUNCTION__
+           << "(" << device_id << ", " << security_origin << ")";
+  filter_->Send(new AudioHostMsg_SwitchOutputDevice(stream_id_,
+                                                    device_id,
+                                                    security_origin,
+                                                    render_frame_id_,
+                                                    request_id));
+}
+
 void AudioMessageFilter::Send(IPC::Message* message) {
   DCHECK(io_message_loop_->BelongsToCurrentThread());
   if (!sender_) {
@@ -126,6 +147,8 @@ bool AudioMessageFilter::OnMessageReceived(const IPC::Message& message) {
   IPC_BEGIN_MESSAGE_MAP(AudioMessageFilter, message)
     IPC_MESSAGE_HANDLER(AudioMsg_NotifyStreamCreated, OnStreamCreated)
     IPC_MESSAGE_HANDLER(AudioMsg_NotifyStreamStateChanged, OnStreamStateChanged)
+    IPC_MESSAGE_HANDLER(AudioMsg_NotifyOutputDeviceSwitched,
+                        OnOutputDeviceSwitched)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -196,4 +219,20 @@ void AudioMessageFilter::OnStreamStateChanged(
   delegate->OnStateChanged(state);
 }
 
+void AudioMessageFilter::OnOutputDeviceSwitched(
+    int stream_id,
+    int request_id,
+    media::AudioOutputIPCDelegate::DeviceSwitchResult result) {
+  DCHECK(io_message_loop_->BelongsToCurrentThread());
+  DVLOG(1) << __FUNCTION__
+           << "(" << stream_id << ", " << request_id << ", " << result << ")";
+  media::AudioOutputIPCDelegate* delegate = delegates_.Lookup(stream_id);
+  if (!delegate) {
+    DLOG(WARNING) << "Got OnOutputDeviceSwitched() event for a nonexistent or"
+                  << " removed audio renderer.  State: " << result;
+    return;
+  }
+  delegate->OnDeviceSwitched(request_id, result);
+}
+
 }  // namespace content