Add a translator comment for the "Sorry, that didn't work. Please try
again." string, as suggested by several people; this should help
translators what "that" refers to.
* show "Sorry, that didn't work. Please try again."
*/
if (!this._errorMessageLabel.visible && !this._wasDismissed) {
+ /* Translators: "that didn't work" refers to the fact that the
+ * requested authentication was not gained; this can happen
+ * because of an authentication error (like invalid password),
+ * for instance. */
this._errorMessageLabel.set_text(_("Sorry, that didn\'t work. Please try again."));
this._errorMessageLabel.show();
this._infoMessageLabel.hide();