Oilpan: Allocate all EventTarget derived types on the manged heap.

Source/core/events/EventTarget.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 54 matching lines @@
 struct EventTargetData {
     WTF_MAKE_NONCOPYABLE(EventTargetData); WTF_MAKE_FAST_ALLOCATED;
 public:
     EventTargetData();
     ~EventTargetData();
 
     EventListenerMap eventListenerMap;
     OwnPtr<FiringEventIteratorVector> firingEventIterators;
 };
 
-class EventTarget {
+class EventTarget : public WillBeGarbageCollectedMixin {
 public:
     void ref() { refEventTarget(); }
     void deref() { derefEventTarget(); }
 
     virtual const AtomicString& interfaceName() const = 0;
     virtual ExecutionContext* executionContext() const = 0;
 
     virtual Node* toNode();
     virtual DOMWindow* toDOMWindow();
     virtual MessagePort* toMessagePort();
@@ skipping 17 matching lines @@
     EventListener* getAttributeEventListener(const AtomicString& eventType);
 
     bool hasEventListeners() const;
     bool hasEventListeners(const AtomicString& eventType) const;
     bool hasCapturingEventListeners(const AtomicString& eventType);
     const EventListenerVector& getEventListeners(const AtomicString& eventType);
     Vector<AtomicString> eventTypes();
 
     bool fireEventListeners(Event*);
 
+    virtual void trace(Visitor*) { }
+
 protected:
     virtual ~EventTarget();
 
     // Subclasses should likely not override these themselves; instead, they should subclass EventTargetWithInlineData.
     virtual EventTargetData* eventTargetData() = 0;
     virtual EventTargetData& ensureEventTargetData() = 0;
 
 private:
     // Subclasses should likely not override these themselves; instead, they should use the REFCOUNTED_EVENT_TARGET() macro.
     virtual void refEventTarget() = 0;
@@ skipping 93 matching lines @@
     using baseClass::ref; \
     using baseClass::deref; \
 private: \
     virtual void refEventTarget() OVERRIDE FINAL { ref(); } \
     virtual void derefEventTarget() OVERRIDE FINAL { deref(); } \
     typedef int thisIsHereToForceASemiColonAfterThisEventTargetMacro
 
 // Use this macro if your EventTarget subclass is also a subclass of WTF::RefCounted.
 // A ref-counted class that uses a different method of refcounting should use DEFINE_EVENT_TARGET_REFCOUNTING directly.
 // Both of these macros are meant to be placed just before the "public:" section of the class declaration.
-#define REFCOUNTED_EVENT_TARGET(className) DEFINE_EVENT_TARGET_REFCOUNTING(RefCounted<className>)
+#define REFCOUNTED_EVENT_TARGET(className) DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<className>)
 
 #endif // EventTarget_h