Adding new media controls to MediaNotification

content/browser/media/session/media_session_service_impl.cc

Index: content/browser/media/session/media_session_service_impl.cc
diff --git a/content/browser/media/session/media_session_service_impl.cc b/content/browser/media/session/media_session_service_impl.cc
index f0f5431c2300325fc6dee976a70fdfd53b47f572..a9bb2fffc5249cf051d82e2bb991f6cc73d6e492 100644
--- a/content/browser/media/session/media_session_service_impl.cc
+++ b/content/browser/media/session/media_session_service_impl.cc
@@ -14,9 +14,15 @@ namespace content {
 
 MediaSessionServiceImpl::MediaSessionServiceImpl(
     RenderFrameHost* render_frame_host)
-    : render_frame_host_(render_frame_host) {}
+    : render_frame_host_(render_frame_host) {
+  if (MediaSessionImpl* session = GetMediaSession())
+    session->SetMediaSessionService(this);
+}
 
-MediaSessionServiceImpl::~MediaSessionServiceImpl() = default;
+MediaSessionServiceImpl::~MediaSessionServiceImpl() {
+  if (MediaSessionImpl* session = GetMediaSession())

[whywhat, 2016/10/28 16:10:23]

nit: can this be null here and below?
I'd avoid initialization in the if () condition as it may confuse readers
(although it doesn't seem to be forbidden in the style guide and there're about
250 existing cases I found:
https://cs.chromium.org/search/?q=file:%5C.cc+if%5Cs%5C(%5B%5E)%22%5D*?%5Cs%3...

[Zhiqiang Zhang (Slow), 2016/11/01 15:24:15]

Yes, currently we only bind the top-level frame service with MediaSession, so
GetMediaSession() will return null for child frames.
Done for the style.

Actually I should also check if |this| == session->service_ here, fixed in the
new patch.

+    session->SetMediaSessionService(nullptr);
+}
 
 // static
 void MediaSessionServiceImpl::Create(
@@ -43,22 +49,30 @@ void MediaSessionServiceImpl::SetMetadata(
     return;
   }
 
-  WebContentsImpl* contents = static_cast<WebContentsImpl*>(
-      WebContentsImpl::FromRenderFrameHost(render_frame_host_));
-  if (contents)
-    MediaSessionImpl::Get(contents)->SetMetadata(metadata);
+  if (MediaSessionImpl* session = GetMediaSession())
+    session->SetMetadata(metadata);
 }
 
 void MediaSessionServiceImpl::EnableAction(
     blink::mojom::MediaSessionAction action) {
-  // TODO(zqzhang): Plumb this signal to Java. See https://crbug.com/656563
-  NOTIMPLEMENTED();
+  if (MediaSessionImpl* session = GetMediaSession())
+    session->OnMediaSessionEnabledAction(action);
 }
 
 void MediaSessionServiceImpl::DisableAction(
     blink::mojom::MediaSessionAction action) {
-  // TODO(zqzhang): Plumb this signal to Java. See https://crbug.com/656563
-  NOTIMPLEMENTED();
+  if (MediaSessionImpl* session = GetMediaSession())
+    session->OnMediaSessionDisabledAction(action);
+}
+
+MediaSessionImpl* MediaSessionServiceImpl::GetMediaSession() {
+  WebContentsImpl* contents = static_cast<WebContentsImpl*>(
+      WebContentsImpl::FromRenderFrameHost(render_frame_host_));
+  if (!contents)
+    return nullptr;
+  if (render_frame_host_ != contents->GetMainFrame())
+    return nullptr;
+  return MediaSessionImpl::Get(contents);
 }
 
 void MediaSessionServiceImpl::Bind(