Consider subpixel accumulation when invalidating paint

Source/core/rendering/RenderObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 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
@@ skipping 813 matching lines @@
     LayoutRect computePaintInvalidationRect(const RenderLayerModelObject* paintInvalidationContainer) const;
 
     // Returns the rect bounds needed to invalidate the paint of this object, in the coordinate space of the rendering backing of |paintInvalidationContainer|
     LayoutRect boundsRectForPaintInvalidation(const RenderLayerModelObject* paintInvalidationContainer) const;
 
     // Actually do the paint invalidate of rect r for this object which has been computed in the coordinate space
     // of the GraphicsLayer backing of |paintInvalidationContainer|. Note that this coordinaten space is not the same
     // as the local coordinate space of |paintInvalidationContainer| in the presence of layer squashing.
     // If |paintInvalidationContainer| is 0, invalidate paints via the view.
     // FIXME: |paintInvalidationContainer| should never be 0. See crbug.com/363699.
-    void invalidatePaintUsingContainer(const RenderLayerModelObject* paintInvalidationContainer, const IntRect&, InvalidationReason) const;
+    void invalidatePaintUsingContainer(const RenderLayerModelObject* paintInvalidationContainer, const LayoutRect&, InvalidationReason) const;
 
     // Invalidate the paint of the entire object. Called when, e.g., the color of a border changes, or when a border
     // style changes.
     void paintInvalidationForWholeRenderer() const;
 
     // Invalidate the paint of a specific subrectangle within a given object. The rect |r| is in the object's coordinate space.
     void invalidatePaintRectangle(const LayoutRect&) const;
 
     bool invalidatePaintIfNeeded(const RenderLayerModelObject* paintInvalidationContainer,
         const LayoutRect& oldBounds, const LayoutPoint& oldPositionFromPaintInvalidationContainer);
@@ skipping 647 matching lines @@
 void showTree(const WebCore::RenderObject*);
 void showLineTree(const WebCore::RenderObject*);
 void showRenderTree(const WebCore::RenderObject* object1);
 // We don't make object2 an optional parameter so that showRenderTree
 // can be called from gdb easily.
 void showRenderTree(const WebCore::RenderObject* object1, const WebCore::RenderObject* object2);
 
 #endif
 
 #endif // RenderObject_h