[Video] Pause videos with no audio when in the background.

media/blink/webmediaplayer_impl.h

Index: media/blink/webmediaplayer_impl.h
diff --git a/media/blink/webmediaplayer_impl.h b/media/blink/webmediaplayer_impl.h
index 9e0d97c2abd313ee331e6a6cbbdd4132bd35317e..ac80c099c3ec0199b182fdce94cd6a6867b32c6b 100644
--- a/media/blink/webmediaplayer_impl.h
+++ b/media/blink/webmediaplayer_impl.h
@@ -368,6 +368,9 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   // is intended for android.
   bool DoesOverlaySupportMetadata() const;
 
+  // Whether the media should be paused when hidden.
+  bool ShouldPauseWhenHidden() const;
+
   blink::WebLocalFrame* frame_;
 
   // The playback state last reported to |delegate_|, to avoid setting duplicate
@@ -431,6 +434,10 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   bool paused_;
   base::TimeDelta paused_time_;
 
+  // Set if paused automatically when hidden and need to resume when visible.
+  // Reset if paused for any other reason.
+  bool paused_when_hidden_;
+
   // Set when starting, seeking, and resuming (all of which require a Pipeline
   // seek). |seek_time_| is only valid when |seeking_| is true.
   bool seeking_;