Add UseCounters for Event.cancelBubble behavior.

third_party/WebKit/Source/core/events/Event.h

 /*
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 161 matching lines @@
     bool immediatePropagationStopped() const { return m_immediatePropagationStopped; }
     bool wasInitialized() { return m_wasInitialized; }
 
     bool defaultPrevented() const { return m_defaultPrevented; }
     virtual void preventDefault();
     void setDefaultPrevented(bool defaultPrevented) { m_defaultPrevented = defaultPrevented; }
 
     bool defaultHandled() const { return m_defaultHandled; }
     void setDefaultHandled() { m_defaultHandled = true; }
 
-    bool cancelBubble() const { return m_cancelBubble; }
-    void setCancelBubble(bool cancel) { m_cancelBubble = cancel; }
+    bool cancelBubble(ExecutionContext* = nullptr) const { return m_cancelBubble; }
+    void setCancelBubble(ExecutionContext*, bool);
 
     Event* underlyingEvent() const { return m_underlyingEvent.get(); }
     void setUnderlyingEvent(Event*);
 
     bool hasEventPath() { return m_eventPath; }
     EventPath& eventPath() { ASSERT(m_eventPath); return *m_eventPath; }
     void initEventPath(Node&);
 
     HeapVector<Member<EventTarget>> path(ScriptState*) const;
     HeapVector<Member<EventTarget>> deepPath(ScriptState*) const;
@@ skipping 61 matching lines @@
     // WebInputEvent instance.
     double m_platformTimeStamp;
 };
 
 #define DEFINE_EVENT_TYPE_CASTS(typeName) \
     DEFINE_TYPE_CASTS(typeName, Event, event, event->is##typeName(), event.is##typeName())
 
 } // namespace blink
 
 #endif // Event_h