GMC: Add OnAudioOutputSinkChanged delegate message & receiver

The webmedia player delegate will now send IPC messages informing
webcontents observers of changes of audio output devices.
used.

Bug: 1110143
Change-Id: Iac3712ee5015f0bd00176b40e3fad60c5c9361eb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2321767
Commit-Queue: Noah Rose Ledesma <noahrose@google.com>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Matthew Denton <mpdenton@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#794848}

content/browser/media/media_web_contents_observer.cc

@@ -220,6 +220,8 @@ bool MediaWebContentsObserver::OnMessageReceived(
     IPC_MESSAGE_HANDLER(
         MediaPlayerDelegateHostMsg_OnPictureInPictureAvailabilityChanged,
         OnPictureInPictureAvailabilityChanged)
+    IPC_MESSAGE_HANDLER(MediaPlayerDelegateHostMsg_OnAudioOutputSinkChanged,
+                        OnAudioOutputSinkChanged);
     IPC_MESSAGE_HANDLER(MediaPlayerDelegateHostMsg_OnBufferUnderflow,
                         OnBufferUnderflow)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ -375,6 +377,11 @@ void MediaWebContentsObserver::OnPictureInPictureAvailabilityChanged(
       MediaPlayerId(render_frame_host, delegate_id), available);
 }
 
+void MediaWebContentsObserver::OnAudioOutputSinkChanged(
+    RenderFrameHost* render_frame_host,
+    int delegate_id,
+    std::string hashed_device_id) {}
+
 void MediaWebContentsObserver::OnBufferUnderflow(
     RenderFrameHost* render_frame_host,
     int delegate_id) {

content/browser/media/media_web_contents_observer.h

@@ -40,7 +40,7 @@ struct MediaPosition;
 
 namespace gfx {
 class Size;
-}  // namespace size
+}  // namespace gfx
 
 namespace content {
 
@@ -148,6 +148,9 @@ class CONTENT_EXPORT MediaWebContentsObserver : public WebContentsObserver {
   void OnPictureInPictureAvailabilityChanged(RenderFrameHost* render_frame_host,
                                              int delegate_id,
                                              bool available);
+  void OnAudioOutputSinkChanged(RenderFrameHost* render_frame_host,
+                                int delegate_id,
+                                std::string hashed_device_id);
   void OnBufferUnderflow(RenderFrameHost* render_frame_host, int delegate_id);
 
   device::mojom::WakeLock* GetAudioWakeLock();

content/common/media/media_player_delegate_messages.h

@@ -124,6 +124,10 @@ IPC_MESSAGE_ROUTED2(
     int /* delegate_id, distinguishes instances */,
     bool /* picture-in-picture availability */)
 
+IPC_MESSAGE_ROUTED2(MediaPlayerDelegateHostMsg_OnAudioOutputSinkChanged,
+                    int /* delegate_id, distinguishes instances */,
+                    std::string /* hashed_device_id */)
+
 IPC_MESSAGE_ROUTED1(MediaPlayerDelegateHostMsg_OnBufferUnderflow,
                     int /* delegate_id, distinguishes instances */)
 

content/renderer/media/renderer_webmediaplayer_delegate.cc

@@ -224,7 +224,10 @@ void RendererWebMediaPlayerDelegate::DidPictureInPictureAvailabilityChange(
 
 void RendererWebMediaPlayerDelegate::DidAudioOutputSinkChange(
     int delegate_id,
-    const std::string& hashed_device_id) {}
+    const std::string& hashed_device_id) {
+  Send(new MediaPlayerDelegateHostMsg_OnAudioOutputSinkChanged(
+      routing_id(), delegate_id, hashed_device_id));
+}
 
 void RendererWebMediaPlayerDelegate::DidBufferUnderflow(int player_id) {
   Send(new MediaPlayerDelegateHostMsg_OnBufferUnderflow(routing_id(),