MD Settings: indicate extension controlled search engines

chrome/browser/resources/settings/search_engines_page/search_engines_browser_proxy.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.
 
 /**
  * @fileoverview A helper object used from the "Manage search engines" section
  * to interact with the browser.
  */
 
 /**
  * @typedef {{canBeDefault: boolean,
  *            canBeEdited: boolean,
  *            canBeRemoved: boolean,
  *            default: boolean,
  *            displayName: string,
- *            extension: (Object|undefined),
+ *            extension: ({id: string,
+ *                         name: string,
+ *                         canBeDisabled: boolean,
+ *                         icon: string}|undefined),
  *            iconURL: (string|undefined),
  *            isOmniboxExtension: boolean,
  *            keyword: string,
  *            modelIndex: number,
  *            name: string,
  *            url: string,
  *            urlLocked: boolean}}
  * @see chrome/browser/ui/webui/settings/search_engine_manager_handler.cc
  */
 var SearchEngine;
@@ skipping 116 matching lines @@
     setHotwordSearchEnabled: function(enabled) {
       chrome.send('setHotwordSearchEnabled', [enabled]);
     },
   };
 
   return {
     SearchEnginesBrowserProxy: SearchEnginesBrowserProxy,
     SearchEnginesBrowserProxyImpl: SearchEnginesBrowserProxyImpl,
   };
 });