Store repaint rects in the coordinate space of their backing GraphicsLayer.

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 333 matching lines @@
 
     bool hasCompositedMask() const;
     bool hasCompositedClippingMask() const;
     bool needsCompositedScrolling() const { return m_scrollableArea && m_scrollableArea->needsCompositedScrolling(); }
 
     bool clipsCompositingDescendantsWithBorderRadius() const;
 
     RenderLayer* scrollParent() const;
     RenderLayer* clipParent() const;
 
+    // Adjusts the given rect to the coordinate space of the repaint container's GraphicsLayer backing.
+    void mapRectToRepaintBacking(const RenderLayerModelObject* repaintContainer, LayoutRect&) const;
+
+    // Computes the bounding repaint rect for this layer, in the coordinate space of the repaint container's GraphicsLayer backing.
+    LayoutRect computeRepaintRect(const RenderLayerModelObject* repaintContainer) const;
+
     bool needsCompositingLayersRebuiltForClip(const RenderStyle* oldStyle, const RenderStyle* newStyle) const;
     bool needsCompositingLayersRebuiltForOverflow(const RenderStyle* oldStyle, const RenderStyle* newStyle) const;
     bool needsCompositingLayersRebuiltForFilters(const RenderStyle* oldStyle, const RenderStyle* newStyle) const;
     bool needsCompositingLayersRebuiltForBlending(const RenderStyle* oldStyle, const RenderStyle* newStyle) const;
 
     bool paintsWithTransparency(PaintBehavior paintBehavior) const
     {
         return isTransparent() && ((paintBehavior & PaintBehaviorFlattenCompositingLayers) || compositingState() != PaintsIntoOwnBacking);
     }
 
@@ skipping 385 matching lines @@
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const WebCore::RenderLayer*);
 void showLayerTree(const WebCore::RenderObject*);
 #endif
 
 #endif // RenderLayer_h