ViewportFrame::GetFrameForPoint(nsIPresContext* aPresContext,
ViewportFrame::GetFrameForPoint(nsPresContext* aPresContext,
ViewportFrame::GetFrameForPoint(nsIPresContext* aPresContext,                                   const nsPoint& aPoint,                                    nsFramePaintLayer aWhichLayer,                                   nsIFrame**     aFrame){  // this should act like a block, so we need to override  return GetFrameForPointUsing(aPresContext, aPoint, nsnull, aWhichLayer, (aWhichLayer == NS_FRAME_PAINT_LAYER_BACKGROUND), aFrame);}