Fix the pref binding by binding to the object rather than the element

chrome/browser/resources/settings/date_time_page/date_time_page.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview
  * 'cr-settings-date-time-page' is the settings page containing date-time
  * settings.
  *
  * Example:
  *
  *    <core-animated-pages>
  *      <cr-settings-date-time-page prefs="{{prefs}}">
  *      </cr-settings-date-time-page>
  *      ... other pages ...
  *    </core-animated-pages>
  *
  * @group Chrome Settings Elements
  * @element cr-settings-date-time-page
  */
 Polymer({
   is: 'cr-settings-date-time-page',
 
   properties: {
     /**
      * Preferences state.
-     * @type {?CrSettingsPrefsElement}
      */
     prefs: {
       type: Object,
       notify: true
     },
 
     /**
      * Route for the page.
      */
     route: {
@@ skipping 30 matching lines @@
     /**
      * Name of the 'core-icon' to show.
      */
     icon: {
       type: String,
       value: 'device:access-time',
       readOnly: true
     },
   },
 });