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

Source/modules/speech/SpeechSynthesisUtterance.h

Index: Source/modules/speech/SpeechSynthesisUtterance.h
diff --git a/Source/modules/speech/SpeechSynthesisUtterance.h b/Source/modules/speech/SpeechSynthesisUtterance.h
index af149d30a3e905fcd733a7a1dba258031ff8774b..c5fa197daca999800d07c906a71c4fc64857d029 100644
--- a/Source/modules/speech/SpeechSynthesisUtterance.h
+++ b/Source/modules/speech/SpeechSynthesisUtterance.h
@@ -38,7 +38,8 @@
 namespace WebCore {
 
 class SpeechSynthesisUtterance FINAL : public RefCountedWillBeRefCountedGarbageCollected<SpeechSynthesisUtterance>, public PlatformSpeechSynthesisUtteranceClient, public ScriptWrappable, public ContextLifecycleObserver, public EventTargetWithInlineData {
-    DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<SpeechSynthesisUtterance>);
+    REFCOUNTED_EVENT_TARGET(SpeechSynthesisUtterance);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SpeechSynthesisUtterance);
 public:
     static PassRefPtrWillBeRawPtr<SpeechSynthesisUtterance> create(ExecutionContext*, const String&);
 
@@ -77,7 +78,7 @@ public:
 
     PlatformSpeechSynthesisUtterance* platformUtterance() const { return m_platformUtterance.get(); }
 
-    void trace(Visitor*);
+    virtual void trace(Visitor*) OVERRIDE;
 
 private:
     SpeechSynthesisUtterance(ExecutionContext*, const String&);