if (aExtension.Equals(NS_LITERAL_STRING("parts")))
if (aExtension.Equals(NS_LITERAL_STRING(".parts")))
SetPreferredTableList(PRUnichar aChar, nsString& aExtension, nsString& aFamilyList){  PRBool isFontForParts;  if (aExtension.Equals(NS_LITERAL_STRING("parts")))    isFontForParts = PR_TRUE;  else if (aExtension.Equals(NS_LITERAL_STRING("variants")))    isFontForParts = PR_FALSE;  else return; // input is not applicable  // Ensure that this is a valid stretchy operator  PRInt32 k = nsMathMLOperators::FindStretchyOperator(aChar);  if (k != kNotFound) {    // We just want to iterate over the font-family list using the    // callback mechanism that nsFont has...    nsFont font(aFamilyList, 0, 0, 0, 0, 0);    PreferredFontEnumContext context = {k, isFontForParts, 0};    font.EnumerateFamilies(PreferredFontEnumCallback, &context);    if (context.mFontCount) { // at least one font was retained      // Append a null separator      gGlyphTableList->AppendElement(nsnull);    }  }}