Lazy evaluation of event.path by numbering TreeScopes in DFS order for later O(1) queries

Source/core/events/EventPath.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 57 matching lines @@
 
 private:
     EventPath();
 
     NodeEventContext& at(size_t index) { return m_nodeEventContexts[index]; }
 
     void addNodeEventContext(Node*);
 
     void calculatePath();
     void calculateAdjustedTargets();
-    void calculateAdjustedEventPath();
+    void calculateTreeScopePrePostOrderNumbers();
 
     void shrink(size_t newSize) { m_nodeEventContexts.shrink(newSize); }
     void shrinkIfNeeded(const Node* target, const EventTarget* relatedTarget);
 
     void adjustTouchList(const Node*, const TouchList*, WillBeHeapVector<RawPtrWillBeMember<TouchList> > adjustedTouchList, const Vector<TreeScope*>& treeScopes);
 
     typedef HashMap<TreeScope*, RefPtr<TreeScopeEventContext> > TreeScopeEventContextMap;
     TreeScopeEventContext* ensureTreeScopeEventContext(Node* currentTarget, TreeScope*, TreeScopeEventContextMap&);
 
     typedef HashMap<TreeScope*, EventTarget*> RelatedTargetMap;
 
     static void buildRelatedNodeMap(const Node*, RelatedTargetMap&);
     static EventTarget* findRelatedNode(TreeScope*, RelatedTargetMap&);
 
 #ifndef NDEBUG
     static void checkReachability(TreeScope&, TouchList&);
 #endif
 
     Vector<NodeEventContext, 64> m_nodeEventContexts;
     Node* m_node;
     Event* m_event;
     Vector<RefPtr<TreeScopeEventContext> > m_treeScopeEventContexts;
 };
 
 } // namespace
 
 #endif