Fix an issue in fullscreen detector when context is destroyed

third_party/WebKit/Source/core/html/HTMLMediaElement.h

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.h b/third_party/WebKit/Source/core/html/HTMLMediaElement.h
index 780d824d381f1d5eb6c75321b7056bebdced5025..e25edccd8ec1f0b8fc419b7b113378d2ec3522b4 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.h
@@ -362,7 +362,7 @@ class CORE_EXPORT HTMLMediaElement
   bool isInteractiveContent() const final;
 
   // SuspendableObject functions.
-  void contextDestroyed(ExecutionContext*) final;
+  void contextDestroyed(ExecutionContext*) override;
 
   virtual void updateDisplayState() {}
 
@@ -739,6 +739,7 @@ class CORE_EXPORT HTMLMediaElement
   friend class MediaControlsTest;
   friend class HTMLMediaElementTest;
   friend class HTMLMediaElementEventListenersTest;
+  friend class HTMLVideoElement;
   friend class HTMLVideoElementTest;
   friend class MediaControlsOrientationLockDelegateTest;