Make Event RefCountedGarbageCollected and implement trace() methods to the Event hierarcy

Source/core/events/MouseEvent.cpp

 /*
  * 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, 2005, 2006, 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 172 matching lines @@
 
 Node* MouseEvent::fromElement() const
 {
     // MSIE extension - "object from which activation or the mouse pointer is exiting during the event" (huh?)
     if (type() != EventTypeNames::mouseout && type() != EventTypeNames::mouseleave)
         return relatedTarget() ? relatedTarget()->toNode() : 0;
 
     return target() ? target()->toNode() : 0;
 }
 
+void MouseEvent::trace(Visitor* visitor)
+{
+    visitor->trace(m_clipboard);
+    MouseRelatedEvent::trace(visitor);
+}
+
 PassRefPtr<SimulatedMouseEvent> SimulatedMouseEvent::create(const AtomicString& eventType, PassRefPtr<AbstractView> view, PassRefPtr<Event> underlyingEvent)
 {
     return adoptRef(new SimulatedMouseEvent(eventType, view, underlyingEvent));
 }
 
 SimulatedMouseEvent::~SimulatedMouseEvent()
 {
 }
 
 SimulatedMouseEvent::SimulatedMouseEvent(const AtomicString& eventType, PassRefPtr<AbstractView> view, PassRefPtr<Event> underlyingEvent)
     : MouseEvent(eventType, true, true, view, 0, 0, 0, 0, 0,
                  0, 0,
                  false, false, false, false, 0, nullptr, nullptr, true)
 {
     if (UIEventWithKeyState* keyStateEvent = findEventWithKeyState(underlyingEvent.get())) {
         m_ctrlKey = keyStateEvent->ctrlKey();
         m_altKey = keyStateEvent->altKey();
         m_shiftKey = keyStateEvent->shiftKey();
         m_metaKey = keyStateEvent->metaKey();
     }
     setUnderlyingEvent(underlyingEvent);
 
     if (this->underlyingEvent() && this->underlyingEvent()->isMouseEvent()) {
         MouseEvent* mouseEvent = toMouseEvent(this->underlyingEvent());
         m_screenLocation = mouseEvent->screenLocation();
         initCoordinates(mouseEvent->clientLocation());
     }
 }
 
+void SimulatedMouseEvent::trace(Visitor* visitor)
+{
+    MouseEvent::trace(visitor);
+}
+
 PassRefPtr<MouseEventDispatchMediator> MouseEventDispatchMediator::create(PassRefPtr<MouseEvent> mouseEvent, MouseEventType mouseEventType)
 {
     return adoptRef(new MouseEventDispatchMediator(mouseEvent, mouseEventType));
 }
 
 MouseEventDispatchMediator::MouseEventDispatchMediator(PassRefPtr<MouseEvent> mouseEvent, MouseEventType mouseEventType)
     : EventDispatchMediator(mouseEvent), m_mouseEventType(mouseEventType)
 {
 }
 
@@ skipping 36 matching lines @@
                                      event()->button(), relatedTarget);
     if (event()->defaultHandled())
         doubleClickEvent->setDefaultHandled();
     EventDispatcher::dispatchEvent(dispatcher->node(), MouseEventDispatchMediator::create(doubleClickEvent));
     if (doubleClickEvent->defaultHandled() || doubleClickEvent->defaultPrevented())
         return false;
     return !swallowEvent;
 }
 
 } // namespace WebCore