Support subpixel layout for borders.

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * 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 1102 matching lines @@
     graphicsLayerParentLocation =
         layoutObject()->view()->documentRect().location();
   }
 
   if (compositingContainer &&
       compositingContainer->needsCompositedScrolling()) {
     LayoutBox* layoutBox = toLayoutBox(compositingContainer->layoutObject());
     IntSize scrollOffset = layoutBox->scrolledContentOffset();
     IntPoint scrollOrigin =
         compositingContainer->getScrollableArea()->scrollOrigin();
-    scrollOrigin.move(-layoutBox->borderLeft(), -layoutBox->borderTop());
+    scrollOrigin.move(-layoutBox->borderLeft().toInt(),
+                      -layoutBox->borderTop().toInt());
     graphicsLayerParentLocation = -(scrollOrigin + scrollOffset);
   }
 }
 
 void CompositedLayerMapping::updateAncestorClippingLayerGeometry(
     const PaintLayer* compositingContainer,
     const IntPoint& snappedOffsetFromCompositedAncestor,
     IntPoint& graphicsLayerParentLocation) {
   if (!compositingContainer || !m_ancestorClippingLayer)
     return;
@@ skipping 2335 matching lines @@
   } else if (graphicsLayer == m_decorationOutlineLayer.get()) {
     name = "Decoration Layer";
   } else {
     ASSERT_NOT_REACHED();
   }
 
   return name;
 }
 
 }  // namespace blink