void SetFontFromStyle(nsIRenderingContext* aRC, nsIStyleContext* aSC)
void SetFontFromStyle(nsIRenderingContext* aRC, nsStyleContext* aSC)
void SetFontFromStyle(nsIRenderingContext* aRC, nsIStyleContext* aSC) {  const nsStyleFont *font = (const nsStyleFont*)    aSC->GetStyleData(eStyleStruct_Font);  NS_ASSERTION(font, "invalid font in style context");  if (font) {    const nsStyleVisibility* visibility = (const nsStyleVisibility*)       aSC->GetStyleData(eStyleStruct_Visibility);    NS_ASSERTION(visibility, "invalid visibility in style context");    nsCOMPtr<nsIAtom> langGroup;    if (visibility && visibility->mLanguage) {      visibility->mLanguage->GetLanguageGroup(getter_AddRefs(langGroup));    }    aRC->SetFont(font->mFont, langGroup);  }}