Shrinking EventPath to improve memory usage and performance

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 @@
     DECLARE_TRACE();
     void clear()
     {
         m_nodeEventContexts.clear();
         m_treeScopeEventContexts.clear();
     }
 
 private:
     EventPath();
 
-    void addNodeEventContext(Node&);
-
     void initialize();
     void calculatePath();
     void calculateAdjustedTargets();
     void calculateTreeScopePrePostOrderNumbers();
 
     void shrink(size_t newSize) { ASSERT(!m_windowEventContext); m_nodeEventContexts.shrink(newSize); }
     void shrinkIfNeeded(const Node& target, const EventTarget& relatedTarget);
 
     void adjustTouchList(const TouchList*, WillBeHeapVector<RawPtrWillBeMember<TouchList>> adjustedTouchList, const WillBeHeapVector<RawPtrWillBeMember<TreeScope>>& treeScopes);
 
     typedef WillBeHeapHashMap<RawPtrWillBeMember<TreeScope>, RefPtrWillBeMember<TreeScopeEventContext>> TreeScopeEventContextMap;
     TreeScopeEventContext* ensureTreeScopeEventContext(Node* currentTarget, TreeScope*, TreeScopeEventContextMap&);
 
     typedef WillBeHeapHashMap<RawPtrWillBeMember<TreeScope>, RawPtrWillBeMember<EventTarget>> RelatedTargetMap;
 
     static void buildRelatedNodeMap(const Node&, RelatedTargetMap&);
     static EventTarget* findRelatedNode(TreeScope&, RelatedTargetMap&);
 
 #if ENABLE(ASSERT)
     static void checkReachability(TreeScope&, TouchList&);
 #endif
 
     const NodeEventContext& topNodeEventContext();
 
-    WillBeHeapVector<NodeEventContext, 64> m_nodeEventContexts;
+    WillBeHeapVector<NodeEventContext> m_nodeEventContexts;
     RawPtrWillBeMember<Node> m_node;
     RawPtrWillBeMember<Event> m_event;
     WillBeHeapVector<RefPtrWillBeMember<TreeScopeEventContext>> m_treeScopeEventContexts;
     OwnPtrWillBeMember<WindowEventContext> m_windowEventContext;
 };
 
 } // namespace
 
 #endif