MD Settings: extension-controlled indicators for default search engine

chrome/browser/resources/settings/search_page/search_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
  * 'settings-search-page' is the settings page containing search settings.
  */
 Polymer({
   is: 'settings-search-page',
 
   properties: {
+    prefs: Object,
+
     /**
      * List of default search engines available.
      * @private {!Array<!SearchEngine>}
      */
     searchEngines_: {
       type: Array,
       value: function() { return []; }
     },
+  },
 
-    /** @private {!settings.SearchEnginesBrowserProxy} */
-    browserProxy_: Object,
-  },
+  /** @private {?settings.SearchEnginesBrowserProxy} */
+  browserProxy_: null,
 
   /** @override */
   created: function() {
     this.browserProxy_ = settings.SearchEnginesBrowserProxyImpl.getInstance();
   },
 
   /** @override */
   ready: function() {
     var updateSearchEngines = function(searchEngines) {
       this.set('searchEngines_', searchEngines.defaults);
     }.bind(this);
     this.browserProxy_.getSearchEnginesList().then(updateSearchEngines);
     cr.addWebUIListener('search-engines-changed', updateSearchEngines);
   },
 
   /** @private */
+  onChange_: function() {
+    var select = /** @type {!HTMLSelectElement} */ (this.$$('select'));
+    var searchEngine = this.searchEngines_[select.selectedIndex];
+    this.browserProxy_.setDefaultSearchEngine(searchEngine.modelIndex);
+  },
+
+  /** @private */
+  onDisableExtension_: function() {
+    this.fire('refresh-pref', 'default_search_provider.enabled');
+  },
+
+  /** @private */
   onManageSearchEnginesTap_: function() {
     settings.navigateTo(settings.Route.SEARCH_ENGINES);
   },
-
-  /** @private */
-  onChange_: function(e) {
-    var select = /** @type {!HTMLSelectElement} */ (this.$$('select'));
-    var searchEngine = this.searchEngines_[select.selectedIndex];
-    this.browserProxy_.setDefaultSearchEngine(searchEngine.modelIndex);
-  },
 });