NS_IMETHOD HandleDrag(nsIPresContext* aPresContext, nsGUIEvent *    aEvent, nsEventStatus*  aEventStatus)  { return NS_OK; }
NS_IMETHODIMP nsSliderFrame::HandleDrag(nsIPresContext& aPresContext, nsGUIEvent*     aEvent, nsEventStatus&  aEventStatus) { return NS_OK; }
  NS_IMETHOD HandleDrag(nsIPresContext* aPresContext,                        nsGUIEvent *    aEvent,                        nsEventStatus*  aEventStatus)  { return NS_OK; }