[MD settings] show icon when content settings are controlled by an extension

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:
  *
@@ skipping 72 matching lines @@
     // Lazy-create the drawer the first time it is opened or swiped into view.
     listenOnce(this.$.drawer, 'open-changed', function() {
       this.$.drawerTemplate.if = true;
     }.bind(this));
 
     window.addEventListener('popstate', function(e) {
       this.$.drawer.closeDrawer();
     }.bind(this));
 
     CrPolicyStrings = {
+      controlledSettingExtension:
+          loadTimeData.getString('controlledSettingExtension'),
       controlledSettingPolicy:
           loadTimeData.getString('controlledSettingPolicy'),
       controlledSettingRecommendedMatches:
           loadTimeData.getString('controlledSettingRecommendedMatches'),
       controlledSettingRecommendedDiffers:
           loadTimeData.getString('controlledSettingRecommendedDiffers'),
 // <if expr="chromeos">
       controlledSettingShared:
           loadTimeData.getString('controlledSettingShared'),
       controlledSettingOwner: loadTimeData.getString('controlledSettingOwner'),
@@ skipping 132 matching lines @@
   onMenuButtonTap_: function() {
     this.$.drawer.toggle();
   },
 
   /** @private */
   directionDelegateChanged_: function() {
     this.$.drawer.align = this.directionDelegate.isRtl() ?
         'right' : 'left';
   },
 });