Implement FullScreen using top layer.

third_party/WebKit/Source/core/layout/LayoutVideo.h

 /*
  * Copyright (C) 2007, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 50 matching lines @@
     bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectVideo || LayoutMedia::isOfType(type); }
 
     void paintReplaced(const PaintInfo&, const LayoutPoint&) const override;
 
     void layout() override;
 
     LayoutUnit computeReplacedLogicalWidth(ShouldComputePreferred  = ComputeActual) const override;
     LayoutUnit computeReplacedLogicalHeight() const override;
     LayoutUnit minimumReplacedHeight() const override;
 
-    LayoutUnit offsetLeft() const override;
-    LayoutUnit offsetTop() const override;
-    LayoutUnit offsetWidth() const override;
-    LayoutUnit offsetHeight() const override;
-
     CompositingReasons additionalCompositingReasons() const override;
 
     void updatePlayer();
 
 
     LayoutSize m_cachedImageSize;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutVideo, isVideo());
 
 } // namespace blink
 
 #endif // LayoutVideo_h