Make video.webkitSupportsFullscreen an alias of document.fullscreenEnabled

Source/core/html/HTMLVideoElement.h

Index: Source/core/html/HTMLVideoElement.h
diff --git a/Source/core/html/HTMLVideoElement.h b/Source/core/html/HTMLVideoElement.h
index f02c93aae0b21da1c62f06da44943500a863c69e..9fe7bfa706136387129d0c617498f52d6119f9b9 100644
--- a/Source/core/html/HTMLVideoElement.h
+++ b/Source/core/html/HTMLVideoElement.h
@@ -55,7 +55,7 @@ public:
     unsigned videoHeight() const;
 
     // Fullscreen
-    void webkitEnterFullscreen(ExceptionState&);
+    void webkitEnterFullscreen();
     void webkitExitFullscreen();
     bool webkitSupportsFullscreen();
     bool webkitDisplayingFullscreen();
@@ -98,7 +98,6 @@ private:
     bool isPresentationAttribute(const QualifiedName&) const override;
     void collectStyleForPresentationAttribute(const QualifiedName&, const AtomicString&, MutableStylePropertySet*) override;
     bool hasVideo() const override { return webMediaPlayer() && webMediaPlayer()->hasVideo(); }
-    bool supportsFullscreen() const;
     bool isURLAttribute(const Attribute&) const override;
     const AtomicString imageSourceURL() const override;