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

Source/modules/mediasource/SourceBufferList.h

Index: Source/modules/mediasource/SourceBufferList.h
diff --git a/Source/modules/mediasource/SourceBufferList.h b/Source/modules/mediasource/SourceBufferList.h
index 22eb059cb4a885fbfc67376544220cdd84270bfb..fab0d568869c23cca4b2e7cdf9df4c57472dc649 100644
--- a/Source/modules/mediasource/SourceBufferList.h
+++ b/Source/modules/mediasource/SourceBufferList.h
@@ -43,7 +43,8 @@ class SourceBuffer;
 class GenericEventQueue;
 
 class SourceBufferList FINAL : public RefCountedWillBeRefCountedGarbageCollected<SourceBufferList>, public ScriptWrappable, public EventTargetWithInlineData {
-    DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<SourceBufferList>);
+    REFCOUNTED_EVENT_TARGET(SourceBufferList);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SourceBufferList);
 public:
     static PassRefPtrWillBeRawPtr<SourceBufferList> create(ExecutionContext* context, GenericEventQueue* asyncEventQueue)
     {
@@ -63,7 +64,7 @@ public:
     virtual const AtomicString& interfaceName() const OVERRIDE;
     virtual ExecutionContext* executionContext() const OVERRIDE;
 
-    void trace(Visitor*);
+    virtual void trace(Visitor*) OVERRIDE;
 
 private:
     SourceBufferList(ExecutionContext*, GenericEventQueue*);