Measure Event.returnValue usage in more detail

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 17 matching lines @@
 #include "core/dom/DOMTimeStamp.h"
 #include "core/events/EventPath.h"
 #include "platform/heap/Handle.h"
 #include "wtf/RefCounted.h"
 #include "wtf/text/AtomicString.h"
 
 namespace WebCore {
 
 class EventTarget;
 class EventDispatcher;
+class ExecutionContext;
 class HTMLIFrameElement;
 
 struct EventInit {
     STACK_ALLOCATED();
 public:
     EventInit();
 
     bool bubbles;
     bool cancelable;
 };
@@ skipping 75 matching lines @@
     bool bubbles() const { return m_canBubble; }
     bool cancelable() const { return m_cancelable; }
     DOMTimeStamp timeStamp() const { return m_createTime; }
 
     void stopPropagation() { m_propagationStopped = true; }
     void stopImmediatePropagation() { m_immediatePropagationStopped = true; }
 
     // IE Extensions
     EventTarget* srcElement() const { return target(); } // MSIE extension - "the object that fired the event"
 
-    bool legacyReturnValue() const { return !defaultPrevented(); }
-    void setLegacyReturnValue(bool returnValue) { setDefaultPrevented(!returnValue); }
+    bool legacyReturnValue(ExecutionContext*) const;
+    void setLegacyReturnValue(ExecutionContext*, bool returnValue);
 
     virtual const AtomicString& interfaceName() const;
     bool hasInterface(const AtomicString&) const;
 
     // These events are general classes of events.
     virtual bool isUIEvent() const;
     virtual bool isMouseEvent() const;
     virtual bool isFocusEvent() const;
     virtual bool isKeyboardEvent() const;
     virtual bool isTouchEvent() const;
@@ skipping 64 matching lines @@
     RefPtrWillBeMember<Event> m_underlyingEvent;
     OwnPtrWillBeMember<EventPath> m_eventPath;
 };
 
 #define DEFINE_EVENT_TYPE_CASTS(typeName) \
     DEFINE_TYPE_CASTS(typeName, Event, event, event->is##typeName(), event.is##typeName())
 
 } // namespace WebCore
 
 #endif // Event_h