The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 "use strict";

 const {classes: Cc, interfaces: Ci, utils: Cu} = Components;

 Cu.import("resource://gre/modules/Services.jsm");

 let service = Cc["@mozilla.org/weave/service;1"]

                 .getService(Ci.nsISupports)

                 .wrappedJSObject;

 if (!service.allowPasswordsEngine) {

   let checkbox = document.getElementById("fxa-pweng-chk");

   checkbox.checked = false;

   checkbox.disabled = true;

 }

 addEventListener("dialogaccept", function () {

   let pane = document.getElementById("sync-customize-pane");

   pane.writePreferences(true);

   window.arguments[0].accepted = true;

 });