AppendUTF16toUTF8( const PRUnichar* aSource, nsACString& aDest )
AppendUTF16toUTF8( const nsAString& aSource, nsACString& aDest )
AppendUTF16toUTF8( const PRUnichar* aSource, nsACString& aDest )  {    if (aSource) {      AppendUTF16toUTF8(nsDependentString(aSource), aDest);    }  }