nsCOMPtr<nsIStyleContext> styleContext; aFrame->GetStyleContext(getter_AddRefs(styleContext));
nsStyleContext* styleContext = aFrame->GetStyleContext();
IsPctHeight(nsIFrame* aFrame){  if (aFrame) {    nsCOMPtr<nsIStyleContext> styleContext;    aFrame->GetStyleContext(getter_AddRefs(styleContext));     nsStylePosition* position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);    if (eStyleUnit_Percent == position->mHeight.GetUnit()) {      float percent = position->mHeight.GetPercentValue();      if (percent > 0.0f) {        return PR_TRUE;      }    }  }  return PR_FALSE;}