Change SimulatedMouseEvent's adoptRef() to adoptRefWillBeRefCountedGarbageCollected()

Source/core/events/MouseEvent.h

Index: Source/core/events/MouseEvent.h
diff --git a/Source/core/events/MouseEvent.h b/Source/core/events/MouseEvent.h
index 513bf99d2840f5948020afd57bce27df0d75b6f9..9b3056b72226df6277744b9437974d0a4b476f1d 100644
--- a/Source/core/events/MouseEvent.h
+++ b/Source/core/events/MouseEvent.h
@@ -113,7 +113,7 @@ private:
 
 class SimulatedMouseEvent FINAL : public MouseEvent {
 public:
-    static PassRefPtr<SimulatedMouseEvent> create(const AtomicString& eventType, PassRefPtrWillBeRawPtr<AbstractView>, PassRefPtr<Event> underlyingEvent);
+    static PassRefPtrWillBeRawPtr<SimulatedMouseEvent> create(const AtomicString& eventType, PassRefPtrWillBeRawPtr<AbstractView>, PassRefPtr<Event> underlyingEvent);
     virtual ~SimulatedMouseEvent();
 
     virtual void trace(Visitor*) OVERRIDE;