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

Source/modules/mediasource/SourceBuffer.h

Index: Source/modules/mediasource/SourceBuffer.h
diff --git a/Source/modules/mediasource/SourceBuffer.h b/Source/modules/mediasource/SourceBuffer.h
index 49419c0ababf7ef6981237bcfff9891f07f2acc8..27c14124b83992540e16c8d6552bb0e581fb08a9 100644
--- a/Source/modules/mediasource/SourceBuffer.h
+++ b/Source/modules/mediasource/SourceBuffer.h
@@ -58,7 +58,8 @@ class Stream;
 class TimeRanges;
 
 class SourceBuffer FINAL : public RefCountedWillBeRefCountedGarbageCollected<SourceBuffer>, public ActiveDOMObject, public EventTargetWithInlineData, public ScriptWrappable, public FileReaderLoaderClient {
-    DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<SourceBuffer>);
+    REFCOUNTED_EVENT_TARGET(SourceBuffer);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SourceBuffer);
 public:
     static PassRefPtrWillBeRawPtr<SourceBuffer> create(PassOwnPtr<blink::WebSourceBuffer>, MediaSource*, GenericEventQueue*);
     static const AtomicString& segmentsKeyword();
@@ -97,7 +98,7 @@ public:
     virtual ExecutionContext* executionContext() const OVERRIDE;
     virtual const AtomicString& interfaceName() const OVERRIDE;
 
-    void trace(Visitor*);
+    virtual void trace(Visitor*) OVERRIDE;
 
 private:
     SourceBuffer(PassOwnPtr<blink::WebSourceBuffer>, MediaSource*, GenericEventQueue*);