Make squashing work with subpixel layout

Source/core/rendering/CompositedLayerMapping.h

 /*
  * Copyright (C) 2009, 2010, 2011 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 38 matching lines @@
 // A GraphicsLayerPaintInfo contains all the info needed to paint a partial subtree of RenderLayers into a GraphicsLayer.
 struct GraphicsLayerPaintInfo {
     RenderLayer* renderLayer;
 
     LayoutRect compositedBounds;
 
     // At first, the m_squashingLayer's bounds/location are not known. The value offsetFromSquashingCLM is
     // an intermediate offset for a squashed RenderLayer, described with respect to the CompositedLayerMapping's
     // owning layer that would eventually have the m_squashingLayer. Once the shared GraphicsLayer's bounds are
     // known, then we can trivially convert this offset to m_squashingLayer's space.
-    IntSize offsetFromSquashingCLM;
+    LayoutSize offsetFromSquashingCLM;
 
     // Offset describing where this squashed RenderLayer paints into the shared GraphicsLayer backing.
     IntSize offsetFromRenderer;
 
     GraphicsLayerPaintingPhase paintingPhase;
 
     bool isBackgroundLayer;
 };
 
 // CompositedLayerMapping keeps track of how RenderLayers of the render tree correspond to
@@ skipping 77 matching lines @@
     void animationFinished(const String& name);
 
     LayoutRect compositedBounds() const;
     void setCompositedBounds(const LayoutRect&);
     void updateCompositedBounds();
 
     void updateAfterWidgetResize();
     void positionOverflowControlsLayers(const IntSize& offsetFromRoot);
     bool hasUnpositionedOverflowControlsLayers() const;
 
-    void addRenderLayerToSquashingGraphicsLayer(RenderLayer*, IntSize offsetFromSquashingCLM, size_t nextSquashedLayerIndex);
+    void addRenderLayerToSquashingGraphicsLayer(RenderLayer*, LayoutSize offsetFromSquashingCLM, size_t nextSquashedLayerIndex);
     void finishAccumulatingSquashingLayers(size_t nextSquashedLayerIndex);
 
     // GraphicsLayerClient interface
     virtual void notifyAnimationStarted(const GraphicsLayer*, double wallClockTime, double monotonicTime) OVERRIDE;
     virtual void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect& clip) OVERRIDE;
     virtual bool isTrackingRepaints() const OVERRIDE;
 
     PassOwnPtr<Vector<FloatRect> > collectTrackedRepaintRects() const;
 
 #ifndef NDEBUG
@@ skipping 178 matching lines @@
     bool m_isMainFrameRenderViewLayer;
     bool m_requiresOwnBackingStoreForIntrinsicReasons;
     bool m_requiresOwnBackingStoreForAncestorReasons;
     bool m_canCompositeFilters;
     bool m_backgroundLayerPaintsFixedRootBackground;
 };
 
 } // namespace WebCore
 
 #endif // CompositedLayerMapping_h