It's no longer necessary to special-case this getter in the `GenericFontLoader` case, since the GENERIC build hasn't been using `mozPrintCallback` for years now (furthermore Firefox 63 is really old as well).
It's no longer necessary to special-case this getter in the `GenericFontLoader` case, since the GENERIC build hasn't been using `mozPrintCallback` for years now (furthermore Firefox 63 is really old as well).