MD Settings: Prevent <settings-prefs> from being initialized in guest mode.

chrome/browser/resources/settings/settings_ui/settings_ui.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
  * 'settings-ui' implements the UI for the Settings page.
  *
  * Example:
  *
  *    <settings-ui prefs="{{prefs}}"></settings-ui>
  */
 cr.exportPath('settings');
 assert(!settings.defaultResourceLoaded,
        'settings_ui.js run twice. You probably have an invalid import.');
 /** Global defined when the main Settings script runs. */
 settings.defaultResourceLoaded = true;
 
 Polymer({
   is: 'settings-ui',
 
   properties: {
     /**
      * Preferences state.
      */
     prefs: Object,
 
+    /** @private */
+    isGuestMode_: {
+      type: Boolean,
+      value: loadTimeData.getBoolean('isGuest'),
+    },
+
     /** @type {?settings.DirectionDelegate} */
     directionDelegate: {
       observer: 'directionDelegateChanged_',
       type: Object,
       value: new settings.DirectionDelegateImpl(),
     },
 
     /** @private {boolean} */
     toolbarSpinnerActive_: {
       type: Boolean,
@@ skipping 25 matching lines @@
     // Lazy-create the drawer the first time it is opened or swiped into view.
     var drawer = assert(this.$$('app-drawer'));
     listenOnce(drawer, 'track opened-changed', function() {
       this.$.drawerTemplate.if = true;
     }.bind(this));
 
     window.addEventListener('popstate', function(e) {
       drawer.close();
     }.bind(this));
 
-    if (loadTimeData.getBoolean('isGuest')) {
+    if (this.isGuestMode_) {
       this.pageVisibility_ = {
         people: false,
         onStartup: false,
         reset: false,
 <if expr="not chromeos">
         appearance: false,
         defaultBrowser: false,
         advancedSettings: false,
 </if>
 <if expr="chromeos">
@@ skipping 37 matching lines @@
   onMenuButtonTap_: function() {
     this.$$('app-drawer').toggle();
   },
 
   /** @private */
   directionDelegateChanged_: function() {
     this.$$('app-drawer').align = this.directionDelegate.isRtl() ?
         'right' : 'left';
   },
 });