Use internal hooks for notifying fullscreen changes to media controls

third_party/WebKit/Source/core/html/shadow/MediaControls.h

Index: third_party/WebKit/Source/core/html/shadow/MediaControls.h
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControls.h b/third_party/WebKit/Source/core/html/shadow/MediaControls.h
index 590db6ed0005814993ba95c843bdc2d4848023c6..947d4d4f9a18e65f55faeba46ff9a885520acd2e 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControls.h
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControls.h
@@ -68,6 +68,10 @@ class CORE_EXPORT MediaControls final : public HTMLDivElement {
   void enterFullscreen();
   void exitFullscreen();
 
+  // Called by HTMLMediaElement when the fullscreen element changes.
+  void didEnterFullscreen();
+  void didExitFullscreen();
+
   void showOverlayCastButtonIfNeeded();
   // Update cast button visibility, but don't try to update our panel
   // button visibility for space.
@@ -184,8 +188,6 @@ class CORE_EXPORT MediaControls final : public HTMLDivElement {
   void onTextTracksChanged();
   void onError();
   void onLoadedMetadata();
-  void onEnteredFullscreen();
-  void onExitedFullscreen();
 
   // Internal cast related methods.
   void startedCasting();