GetSubDropFromChild(nsPresContext* aPresContext, nsIFrame*       aChild,
GetSubDropFromChild(nsIFrame*       aChild,
  GetSubDropFromChild(nsPresContext* aPresContext,                      nsIFrame*       aChild,                       nscoord&        aSubDrop)   {    const nsStyleFont* font = aChild->GetStyleFont();    nsCOMPtr<nsIFontMetrics> fm = aPresContext->GetMetricsFor(font->mFont);    GetSubDrop(fm, aSubDrop);  }