[MediaSession] Add playbackState attribute to Blink MediaSession and use it to determine playback s…

content/browser/media/session/media_session_service_impl.cc

 // Copyright 2016 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 "content/browser/media/session/media_session_service_impl.h"
 
 #include "content/browser/media/session/media_metadata_sanitizer.h"
 #include "content/browser/media/session/media_session_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
 
 namespace content {
 
 MediaSessionServiceImpl::MediaSessionServiceImpl(
     RenderFrameHost* render_frame_host)
-    : render_frame_host_(render_frame_host) {
+    : render_frame_host_(render_frame_host),
+      playback_state_(blink::mojom::MediaSessionPlaybackState::NONE) {
   MediaSessionImpl* session = GetMediaSession();
   if (session)
     session->OnServiceCreated(this);
 }
 
 MediaSessionServiceImpl::~MediaSessionServiceImpl() {
   MediaSessionImpl* session = GetMediaSession();
   if (session)
     session->OnServiceDestroyed(this);
 }
 
 // static
 void MediaSessionServiceImpl::Create(
     RenderFrameHost* render_frame_host,
     blink::mojom::MediaSessionServiceRequest request) {
   MediaSessionServiceImpl* impl =
       new MediaSessionServiceImpl(render_frame_host);
   impl->Bind(std::move(request));
 }
 
 void MediaSessionServiceImpl::SetClient(
     blink::mojom::MediaSessionClientPtr client) {
   client_ = std::move(client);
 }
 
+void MediaSessionServiceImpl::SetPlaybackState(
+    blink::mojom::MediaSessionPlaybackState state) {
+  playback_state_ = state;
+  MediaSessionImpl* session = GetMediaSession();
+  if (session)
+    session->OnMediaSessionPlaybackStateChanged(this);
+}
+
 void MediaSessionServiceImpl::SetMetadata(
     const base::Optional<content::MediaMetadata>& metadata) {
   // When receiving a MediaMetadata, the browser process can't trust that it is
   // coming from a known and secure source. It must be processed accordingly.
   if (metadata.has_value() &&
       !MediaMetadataSanitizer::CheckSanity(metadata.value())) {
     render_frame_host_->GetProcess()->ShutdownForBadMessage(
         RenderProcessHost::CrashReportMode::GENERATE_CRASH_DUMP);
     return;
   }
@@ skipping 28 matching lines @@
   return MediaSessionImpl::Get(contents);
 }
 
 void MediaSessionServiceImpl::Bind(
     blink::mojom::MediaSessionServiceRequest request) {
   binding_.reset(new mojo::Binding<blink::mojom::MediaSessionService>(
       this, std::move(request)));
 }
 
 }  // namespace content