nsIScrollableView* scrollable = GetScrollableView(aPresContext);
nsIScrollableView* scrollable = GetScrollableView();
nsGfxScrollFrameInner::ScrollbarChanged(nsIPresContext* aPresContext, nscoord aX, nscoord aY, PRUint32 aFlags){  nsIScrollableView* scrollable = GetScrollableView(aPresContext);  scrollable->ScrollTo(aX, aY, aFlags); // printf("scrolling to: %d, %d\n", aX, aY);}