[Media>UI] Apply throttling if the notification is updated too frequently

content/browser/media/session/media_session_impl.cc

Index: content/browser/media/session/media_session_impl.cc
diff --git a/content/browser/media/session/media_session_impl.cc b/content/browser/media/session/media_session_impl.cc
index 32d55395bd10e52eae21da24f266e66a0ffc52b2..3705d8c524137d6bf98751e4092aaeab9b50a990 100644
--- a/content/browser/media/session/media_session_impl.cc
+++ b/content/browser/media/session/media_session_impl.cc
@@ -331,7 +331,8 @@ void MediaSessionImpl::OnPlayerPaused(MediaSessionPlayerObserver* observer,
 }
 
 void MediaSessionImpl::Resume(SuspendType suspend_type) {
-  DCHECK(IsSuspended());
+  if (!IsSuspended())

[whywhat, 2017/04/20 19:34:59]

Why this change?

[Zhiqiang Zhang (Slow), 2017/04/20 21:40:44]

As we now throttle the notifications, the notification is more likely to be
out-of-sync with the latest info. Therefore the notification might send an
action that MediaSession no longer accepts.

+    return;
 
   if (suspend_type == SuspendType::UI) {
     MediaSessionUmaHelper::RecordMediaSessionUserAction(