Don't emptify event.path after dispatching an event.

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 37 matching lines @@
 };
 
 class EventPath FINAL : public NoBaseWillBeGarbageCollected<EventPath> {
 public:
     explicit EventPath(Event*);
     explicit EventPath(Node*);
     void resetWith(Node*);
 
     NodeEventContext& operator[](size_t index) { return m_nodeEventContexts[index]; }
     const NodeEventContext& operator[](size_t index) const { return m_nodeEventContexts[index]; }
-    const NodeEventContext& last() const { return m_nodeEventContexts[size() - 1]; }
+    NodeEventContext& last() { return m_nodeEventContexts[size() - 1]; }
 
     bool isEmpty() const { return m_nodeEventContexts.isEmpty(); }
     size_t size() const { return m_nodeEventContexts.size(); }
 
     void adjustForRelatedTarget(Node*, EventTarget* relatedTarget);
     void adjustForTouchEvent(Node*, TouchEvent&);
 
     static EventTarget* eventTargetRespectingTargetRules(Node*);
 
     void trace(Visitor*);
@@ skipping 28 matching lines @@
 
     WillBeHeapVector<NodeEventContext, 64> m_nodeEventContexts;
     RawPtrWillBeMember<Node> m_node;
     RawPtrWillBeMember<Event> m_event;
     WillBeHeapVector<RefPtrWillBeMember<TreeScopeEventContext> > m_treeScopeEventContexts;
 };
 
 } // namespace
 
 #endif