Oilpan: Replace most of RefPtrs for Event objects with oilpan's transition types

Source/modules/mediastream/MediaStream.h

Index: Source/modules/mediastream/MediaStream.h
diff --git a/Source/modules/mediastream/MediaStream.h b/Source/modules/mediastream/MediaStream.h
index 0334b5e76820aea949ac4451d2a572dc89188d34..8ecd6f628a7c938954db363a28a93cdc1ab5c9dc 100644
--- a/Source/modules/mediastream/MediaStream.h
+++ b/Source/modules/mediastream/MediaStream.h
@@ -95,7 +95,7 @@ private:
     virtual void addRemoteTrack(MediaStreamComponent*) OVERRIDE;
     virtual void removeRemoteTrack(MediaStreamComponent*) OVERRIDE;
 
-    void scheduleDispatchEvent(PassRefPtr<Event>);
+    void scheduleDispatchEvent(PassRefPtrWillBeRawPtr<Event>);
     void scheduledEventTimerFired(Timer<MediaStream>*);
 
     bool m_stopped;
@@ -105,7 +105,7 @@ private:
     RefPtr<MediaStreamDescriptor> m_descriptor;
 
     Timer<MediaStream> m_scheduledEventTimer;
-    Vector<RefPtr<Event> > m_scheduledEvents;
+    WillBePersistentHeapVector<RefPtrWillBeMember<Event> > m_scheduledEvents;
 };
 
 typedef Vector<RefPtr<MediaStream> > MediaStreamVector;