Fix fullscreen elements in pinch viewport mode.

Source/core/frame/PinchViewport.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 61 matching lines @@
 
     void attachToLayerTree(GraphicsLayer*, GraphicsLayerFactory*);
     GraphicsLayer* rootGraphicsLayer()
     {
         return m_rootTransformLayer.get();
     }
     GraphicsLayer* containerLayer()
     {
         return m_innerViewportContainerLayer.get();
     }
+    GraphicsLayer* scrollLayer()
+    {
+        return m_innerViewportScrollLayer.get();
+    }
 
     // Sets the location of the inner viewport relative to the outer viewport. The
     // coordinates are in partial CSS pixels.
     void setLocation(const FloatPoint&);
     void move(const FloatPoint&);
     FloatPoint location() const { return m_offset; }
 
     // Sets the size of the inner viewport when unscaled in CSS pixels.
     // This will be clamped to the size of the outer viewport (the main frame).
     void setSize(const IntSize&);
@@ skipping 85 matching lines @@
 
     // Offset of the pinch viewport from the main frame's origin, in CSS pixels.
     FloatPoint m_offset;
     float m_scale;
     IntSize m_size;
 };
 
 } // namespace blink
 
 #endif // PinchViewport_h