fix quick unlock config in options

chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('options', function() {
   var Page = cr.ui.pageManager.Page;
   var PageManager = cr.ui.pageManager.PageManager;
 
   /**
+   * Maximum time to wait after the page is fully loaded before we start to
+   * load polymer elements.
+   * @type {number}
+   * @const
+   */
+  var POLYMER_LOAD_TIMEOUT_MS = 5000;
+
+  /**
    * QuickUnlockConfigureOverlay class
    * Dialog that allows users to configure screen lock.
    * @constructor
    * @extends {cr.ui.pageManager.Page}
    */
   function QuickUnlockConfigureOverlay() {
     Page.call(this, 'quickUnlockConfigureOverlay',
               loadTimeData.getString('lockScreenTitle'),
               'quick-unlock-configure-overlay');
 
   }
 
   cr.addSingletonGetter(QuickUnlockConfigureOverlay);
 
   QuickUnlockConfigureOverlay.prototype = {
     __proto__: Page.prototype,
 
     /** @override */
     initializePage: function() {
       Page.prototype.initializePage.call(this);
       $('screen-lock-done').onclick = function() {
         QuickUnlockConfigureOverlay.dismiss();
       };
+
+      window.addEventListener('load', function() {
+        // Setting a timeout here to avoid racing with some browsertests,
+        // this should be here for only a short period of time as
+        // md-settings are launching soon.
+        setTimeout(
+            this.ensurePolymerIsLoaded_.bind(this), POLYMER_LOAD_TIMEOUT_MS);
+      }.bind(this));
     },
 
     /** @override */
     didClosePage: function() {
       settings.navigateTo(settings.Route.PEOPLE);
     },
 
     /** @override */
     didShowPage: function() {
       this.ensurePolymerIsLoaded_().then(this.onPolymerLoaded_.bind(this));
@@ skipping 15 matching lines @@
     },
 
     /**
      * Called when polymer has been loaded and the dialog should be displayed.
      * @private
      */
     onPolymerLoaded_: function() {
       settings.navigateTo(settings.Route.LOCK_SCREEN);
       var lockScreen = document.querySelector('settings-lock-screen');
 
-      var checkbox =
-          lockScreen.root.querySelector(
-              'div.settings-box.single-column.screen-lock');
+      var checkbox = lockScreen.root.querySelector('div.settings-box');
       checkbox.hidden = true;
 
       var passwordPrompt = lockScreen.root.
           querySelector('settings-password-prompt-dialog');
       passwordPrompt.addEventListener('close', function() {
         if (!lockScreen.setModes_) {
           QuickUnlockConfigureOverlay.dismiss();
         }
       }.bind(this));
     },
   };
 
   QuickUnlockConfigureOverlay.dismiss = function() {
     PageManager.closeOverlay();
   };
 
   // Export
   return {
     QuickUnlockConfigureOverlay: QuickUnlockConfigureOverlay
   };
 });