Force the video to go fullscreen when setting persistent video

media/blink/webmediaplayer_delegate.h

Index: media/blink/webmediaplayer_delegate.h
diff --git a/media/blink/webmediaplayer_delegate.h b/media/blink/webmediaplayer_delegate.h
index 40715e1efa144514ecb024f2c744205373222f03..c756e3ce49fc9d575ce43b0496333e0444d592c1 100644
--- a/media/blink/webmediaplayer_delegate.h
+++ b/media/blink/webmediaplayer_delegate.h
@@ -54,6 +54,10 @@ class WebMediaPlayerDelegate {
     // |player_volume| * |multiplier|. The range of |multiplier| is [0, 1],
     // where 1 indicates normal (non-ducked) playback.
     virtual void OnVolumeMultiplierUpdate(double multiplier) = 0;
+
+    // Called to set as the persistent video. A persistent video should hide its
+    // controls and go fullscreen.
+    virtual void OnBecamePersistentVideo(bool value) = 0;
   };
 
   // Returns true if the host frame is hidden or closed.