Track scissored damage area for WebGL

Source/core/rendering/RenderLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 123 matching lines @@
     IntSize size() const;
 
     LayoutRect rect() const { return LayoutRect(location(), LayoutSize(size())); }
 
     bool isRootLayer() const { return m_isRootLayer; }
 
     RenderLayerCompositor* compositor() const;
 
     // Notification from the renderer that its content changed (e.g. current frame of image changed).
     // Allows updates of layer content without invalidating paint.
-    void contentChanged(ContentChangeType);
+    void contentChanged(ContentChangeType, const IntRect&);
 
     void updateLayerPositionsAfterLayout();
 
     bool isPaginated() const { return m_isPaginated; }
     RenderLayer* enclosingPaginationLayer() const { return m_enclosingPaginationLayer; }
 
     void updateTransformationMatrix();
     RenderLayer* renderingContextRoot();
 
     // Our current relative position offset.
@@ skipping 527 matching lines @@
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const blink::RenderLayer*);
 void showLayerTree(const blink::RenderObject*);
 #endif
 
 #endif // RenderLayer_h