data->metrics->DrawStringCallback(aChar, aFont, aData);
return data->metrics->DrawStringCallback(aString, aLen, aFont, aData);
StaticDrawStringCallback(FcChar32 aChar, nsFontXft *aFont, void *aData){    DrawStringData *data = (DrawStringData *)aData;    data->metrics->DrawStringCallback(aChar, aFont, aData);}