Allow proper highlighting on universal overflow scroll.

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 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 625 matching lines @@
     if (renderView && renderView->compositor() && renderView->compositor()->staleInCompositingMode())
         m_page->mainFrame()->view()->scheduleAnimation();
 
     m_touchEventTargetRectsAreDirty = true;
 }
 
 void ScrollingCoordinator::updateScrollParentForGraphicsLayer(GraphicsLayer* child, RenderLayer* parent)
 {
     WebLayer* scrollParentWebLayer = 0;
     if (parent && parent->hasCompositedLayerMapping())
-        scrollParentWebLayer = toWebLayer(parent->compositedLayerMapping()->parentForSublayers());
+        scrollParentWebLayer = toWebLayer(parent->compositedLayerMapping()->scrollingContentsLayer());
 
     child->setScrollParent(scrollParentWebLayer);
 }
 
 void ScrollingCoordinator::updateClipParentForGraphicsLayer(GraphicsLayer* child, RenderLayer* parent)
 {
     WebLayer* clipParentWebLayer = 0;
     if (parent && parent->hasCompositedLayerMapping())
         clipParentWebLayer = toWebLayer(parent->compositedLayerMapping()->parentForSublayers());
 
@@ skipping 328 matching lines @@
     bool frameIsScrollable = frameView && frameView->isScrollable();
     if (frameIsScrollable != m_wasFrameScrollable)
         return true;
 
     if (WebLayer* scrollLayer = frameView ? toWebLayer(frameView->layerForScrolling()) : 0)
         return blink::WebSize(frameView->contentsSize()) != scrollLayer->bounds();
     return false;
 }
 
 } // namespace WebCore