Implement a Hit Test Cache.

Source/core/paint/DeprecatedPaintLayerStackingNode.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 82 matching lines @@
 
     DeprecatedPaintLayer* layer() const { return m_layer; }
 
 #if ENABLE(ASSERT)
     bool layerListMutationAllowed() const { return m_layerListMutationAllowed; }
     void setLayerListMutationAllowed(bool flag) { m_layerListMutationAllowed = flag; }
 #endif
 
     // The hitTest() method looks for mouse events by walking layers that intersect the point from front to back.
     bool hitTest(HitTestResult&);
-    bool hitTest(const HitTestRequest&, const HitTestLocation&, HitTestResult&);
 
 private:
     friend class DeprecatedPaintLayerStackingNodeIterator;
     friend class DeprecatedPaintLayerStackingNodeReverseIterator;
     friend class LayoutTreeAsText;
 
     Vector<DeprecatedPaintLayerStackingNode*>* posZOrderList() const
     {
         ASSERT(!m_zOrderListsDirty);
         ASSERT(isStackingContext() || !m_posZOrderList);
@@ skipping 99 matching lines @@
 
 private:
     DeprecatedPaintLayerStackingNode* m_stackingNode;
     bool m_previousMutationAllowedState;
 };
 #endif
 
 } // namespace blink
 
 #endif // DeprecatedPaintLayerStackingNode_h