Fix overflow:overlay scrollbar width for paint.

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 532 matching lines @@
 
   // We ignore overflow clip here; we want composited overflow content to
   // behave as if it lives in an unclipped universe so it can prepaint, etc.
   // This means that we need to check if we are actually clipped before
   // setting up m_ancestorClippingLayer otherwise
   // updateAncestorClippingLayerGeometry will fail as the clip rect will be
   // infinite.
   // FIXME: this should use cached clip rects, but this sometimes give
   // inaccurate results (and trips the ASSERTS in PaintLayerClipper).
   ClipRectsContext clipRectsContext(compositingAncestor, UncachedClipRects,
-                                    IgnoreOverlayScrollbarSize);
+                                    IgnorePlatformOverlayScrollbarSize);
   clipRectsContext.setIgnoreOverflowClip();
 
   ClipRect clipRect;
   m_owningLayer.clipper(PaintLayer::DoNotUseGeometryMapper)
       .calculateBackgroundClipRect(clipRectsContext, clipRect);
   IntRect parentClipRect = pixelSnappedIntRect(clipRect.rect());
   owningLayerIsClipped = parentClipRect != LayoutRect::infiniteIntRect();
 
   // TODO(schenney): CSS clips are not applied to composited children, and
   // should be via mask or by compositing the parent too.
@@ skipping 591 matching lines @@
 
 void CompositedLayerMapping::updateAncestorClippingLayerGeometry(
     const PaintLayer* compositingContainer,
     const IntPoint& snappedOffsetFromCompositedAncestor,
     IntPoint& graphicsLayerParentLocation) {
   if (!compositingContainer || !m_ancestorClippingLayer)
     return;
 
   ClipRectsContext clipRectsContext(compositingContainer,
                                     PaintingClipRectsIgnoringOverflowClip,
-                                    IgnoreOverlayScrollbarSize);
+                                    IgnorePlatformOverlayScrollbarSize);
 
   ClipRect parentClipRect;
   m_owningLayer.clipper(PaintLayer::DoNotUseGeometryMapper)
       .calculateBackgroundClipRect(clipRectsContext, parentClipRect);
 
   IntRect snappedParentClipRect(pixelSnappedIntRect(parentClipRect.rect()));
 
   DCHECK(snappedParentClipRect != LayoutRect::infiniteIntRect());
   m_ancestorClippingLayer->setPosition(FloatPoint(
       snappedParentClipRect.location() - graphicsLayerParentLocation));
@@ skipping 2322 matching lines @@
   } else if (graphicsLayer == m_decorationOutlineLayer.get()) {
     name = "Decoration Layer";
   } else {
     ASSERT_NOT_REACHED();
   }
 
   return name;
 }
 
 }  // namespace blink