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

Source/core/html/track/TextTrackList.h

Index: Source/core/html/track/TextTrackList.h
diff --git a/Source/core/html/track/TextTrackList.h b/Source/core/html/track/TextTrackList.h
index ca97fb1e6942675a899175423e53b9b3f0d5d77a..32e26b1cf37b75a187e978b388a539258438861e 100644
--- a/Source/core/html/track/TextTrackList.h
+++ b/Source/core/html/track/TextTrackList.h
@@ -42,7 +42,8 @@ class GenericEventQueue;
 class TextTrack;
 
 class TextTrackList FINAL : public RefCountedWillBeRefCountedGarbageCollected<TextTrackList>, public ScriptWrappable, public EventTargetWithInlineData {
-    DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<TextTrackList>);
+    REFCOUNTED_EVENT_TARGET(TextTrackList);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(TextTrackList);
 public:
     static PassRefPtrWillBeRawPtr<TextTrackList> create(HTMLMediaElement* owner)
     {
@@ -76,7 +77,7 @@ public:
     void scheduleChangeEvent();
     void removeAllInbandTracks();
 
-    void trace(Visitor*);
+    virtual void trace(Visitor*) OVERRIDE;
 
 private:
     explicit TextTrackList(HTMLMediaElement*);