Oilpan: Prepare to move EventDispatchMediator to Oilpan heap.

Source/core/events/EventDispatchMediator.h

Index: Source/core/events/EventDispatchMediator.h
diff --git a/Source/core/events/EventDispatchMediator.h b/Source/core/events/EventDispatchMediator.h
index 5c0376653aa75433ded231a6efdcd277d621e8e5..233c442273cae6cfbafffd6648157d04485e49af 100644
--- a/Source/core/events/EventDispatchMediator.h
+++ b/Source/core/events/EventDispatchMediator.h
@@ -42,10 +42,11 @@ class Event;
 class EventDispatcher;
 class Node;
 
-class EventDispatchMediator : public RefCounted<EventDispatchMediator> {
+class EventDispatchMediator : public RefCountedWillBeGarbageCollectedFinalized<EventDispatchMediator> {
 public:
-    static PassRefPtr<EventDispatchMediator> create(PassRefPtrWillBeRawPtr<Event>);
+    static PassRefPtrWillBeRawPtr<EventDispatchMediator> create(PassRefPtrWillBeRawPtr<Event>);
     virtual ~EventDispatchMediator() { };
+    virtual void trace(Visitor*);
     virtual bool dispatchEvent(EventDispatcher*) const;
     Event* event() const { return m_event.get(); };
 
@@ -55,7 +56,7 @@ protected:
     void setEvent(PassRefPtrWillBeRawPtr<Event> event) { m_event = event; };
 
 private:
-    RefPtrWillBePersistent<Event> m_event;
+    RefPtrWillBeMember<Event> m_event;
 };
 
 } // namespace WebCore