Support subtitles for native fullscreen video

Source/core/rendering/RenderLayerModelObject.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010, 2012 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 10 matching lines @@
  */
 
 #ifndef RenderLayerModelObject_h
 #define RenderLayerModelObject_h
 
 #include "core/rendering/RenderObject.h"
 
 namespace WebCore {
 
 class RenderLayer;
+class RenderLayerBacking;
 class ScrollableArea;
 
 class RenderLayerModelObject : public RenderObject {
 public:
     explicit RenderLayerModelObject(ContainerNode*);
     virtual ~RenderLayerModelObject();
 
     // Called by RenderObject::willBeDestroyed() and is the only way layers should ever be destroyed
     void destroyLayer();
 
     bool hasSelfPaintingLayer() const;
     RenderLayer* layer() const { return m_layer; }
     ScrollableArea* scrollableArea() const;
 
     virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle) OVERRIDE;
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
     virtual void updateFromStyle() { }
 
     virtual bool requiresLayer() const = 0;
 
     // Returns true if the background is painted opaque in the given rect.
     // The query rect is given in local coordinate system.
     virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const { return false; }
 
     // This is null for anonymous renderers.
     ContainerNode* node() const { return toContainerNode(RenderObject::node()); }
 
+    RenderLayerBacking* backing() const;
+
 protected:
     void ensureLayer();
 
     virtual void willBeDestroyed() OVERRIDE;
 
     virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer*, const LayoutPoint&, const LayoutRect&) const OVERRIDE;
 
 private:
     virtual bool isLayerModelObject() const OVERRIDE FINAL { return true; }
 
@@ skipping 17 matching lines @@
     ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isLayerModelObject());
     return static_cast<const RenderLayerModelObject*>(object);
 }
 
 // This will catch anyone doing an unnecessary cast.
 void toRenderLayerModelObject(const RenderLayerModelObject*);
 
 } // namespace WebCore
 
 #endif // RenderLayerModelObject_h