Change the URL for the Extension Settings page from chrome://settings/extensionSettings to chrome...

chrome/browser/resources/options/extension_settings.js

 // Copyright (c) 2011 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.
 
 // Used for observing function of the backend datasource for this page by
 // tests.
 var webui_responded_ = false;
 
 cr.define('options', function() {
   var OptionsPage = options.OptionsPage;
   var ExtensionsList = options.ExtensionsList;
 
   /**
    * ExtensionSettings class
    * Encapsulated handling of the 'Manage Extensions' page.
    * @class
    */
   function ExtensionSettings() {
     OptionsPage.call(this,
-                     'extensionSettings',
+                     'extensions',
                      templateData.extensionSettingsTitle,
                      'extension-settings');
   }
 
   cr.addSingletonGetter(ExtensionSettings);
 
   ExtensionSettings.prototype = {
     __proto__: OptionsPage.prototype,
 
     /**
@@ skipping 145 matching lines @@
 
     var extensionList = $('extension-settings-list');
     ExtensionsList.decorate(extensionList);
   }
 
   // Export
   return {
     ExtensionSettings: ExtensionSettings
   };
 });