if (!mXftFont && !GetXftFont()) return NS_ERROR_NOT_AVAILABLE;
NS_PRECONDITION(mXftFont, "FindFont should not return bad fonts");
nsFontXft::GetTextExtents32(const FcChar32 *aString, PRUint32 aLen,                             XGlyphInfo &aGlyphInfo){    if (!mXftFont && !GetXftFont())            return NS_ERROR_NOT_AVAILABLE;    // NS_CONST_CAST needed for older versions of Xft    XftTextExtents32(GDK_DISPLAY(), mXftFont,                     NS_CONST_CAST(FcChar32*, aString), aLen, &aGlyphInfo);    return NS_OK;}