Compositor hit test performance improvement

Source/core/rendering/RenderLayerModelObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010, 2012 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 164 matching lines @@
         bool oldStyleIsViewportConstrained = oldStyle && oldStyle->hasViewportConstrainedPosition();
         if (newStyleIsViewportConstained != oldStyleIsViewportConstrained) {
             if (newStyleIsViewportConstained && layer())
                 frameView->addViewportConstrainedObject(this);
             else
                 frameView->removeViewportConstrainedObject(this);
         }
     }
 }
 
-void RenderLayerModelObject::addLayerHitTestRects(LayerHitTestRects& rects, const RenderLayer* currentLayer, const LayoutPoint& layerOffset) const
+void RenderLayerModelObject::addLayerHitTestRects(LayerHitTestRects& rects, const RenderLayer* currentLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const
 {
     // If we have a new layer then our current layer/offset is irrelevant.
     LayoutPoint adjustedLayerOffset = layerOffset;
+    LayoutRect adjustedContainerRect = containerRect;
     if (hasLayer()) {
         currentLayer = layer();
         adjustedLayerOffset = LayoutPoint();
+        adjustedContainerRect = LayoutRect();
     }
 
-    RenderObject::addLayerHitTestRects(rects, currentLayer, adjustedLayerOffset);
+    RenderObject::addLayerHitTestRects(rects, currentLayer, adjustedLayerOffset, adjustedContainerRect);
 }
 
 } // namespace WebCore