Revert "Remove the HTMLVideoElement-specific prefixed fullscreen API"

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 31690dddc622673e663c1ebe0a0dc22a8d9af0cd..e758f9f88910a939def2e6b8d0591330088712f4 100644
--- a/Source/core/html/HTMLVideoElement.h
+++ b/Source/core/html/HTMLVideoElement.h
@@ -44,6 +44,12 @@ public:
     unsigned videoWidth() const;
     unsigned videoHeight() const;
 
+    // Fullscreen
+    void webkitEnterFullscreen(ExceptionState&);
+    void webkitExitFullscreen();
+    bool webkitSupportsFullscreen();
+    bool webkitDisplayingFullscreen();
+
     // Statistics
     unsigned webkitDecodedFrameCount() const;
     unsigned webkitDroppedFrameCount() const;
@@ -73,6 +79,7 @@ private:
     virtual void collectStyleForPresentationAttribute(const QualifiedName&, const AtomicString&, MutableStylePropertySet*) OVERRIDE;
     virtual bool isVideo() const OVERRIDE { return true; }
     virtual bool hasVideo() const OVERRIDE { return player() && player()->hasVideo(); }
+    bool supportsFullscreen() const;
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
     virtual const AtomicString imageSourceURL() const OVERRIDE;