Remove tons of OILPAN.

sky/engine/core/events/MouseEvent.h

Index: sky/engine/core/events/MouseEvent.h
diff --git a/sky/engine/core/events/MouseEvent.h b/sky/engine/core/events/MouseEvent.h
index 39e8c833ad2bf7a692be4351cf44c1f9ca6b3360..46a413656b03e579a8ca2c66146a1915ade4a726 100644
--- a/sky/engine/core/events/MouseEvent.h
+++ b/sky/engine/core/events/MouseEvent.h
@@ -91,8 +91,6 @@ public:
     virtual bool isDragEvent() const override final;
     virtual int which() const override final;
 
-    virtual void trace(Visitor*) override;
-
 protected:
     MouseEvent(const AtomicString& type, bool canBubble, bool cancelable, PassRefPtr<AbstractView>,
         int detail, int screenX, int screenY, int pageX, int pageY,
@@ -117,8 +115,6 @@ public:
     static PassRefPtr<SimulatedMouseEvent> create(const AtomicString& eventType, PassRefPtr<AbstractView>, PassRefPtr<Event> underlyingEvent);
     virtual ~SimulatedMouseEvent();
 
-    virtual void trace(Visitor*) override;
-
 private:
     SimulatedMouseEvent(const AtomicString& eventType, PassRefPtr<AbstractView>, PassRefPtr<Event> underlyingEvent);
 };