nsACString::const_iterator source_start, source_end; CalculateUTF8Length calculator; copy_string(aSource.BeginReading(source_start), aSource.EndReading(source_end), calculator);
AppendUTF8toUTF16( const nsACString& aSource, nsAString& aDest )  {    // This isn't the fastest possible implementation of this method,    // but it works, and that's better than nothing!    aDest.Append(NS_ConvertUTF8toUCS2(aSource));  }