[MD Extensions] Implement opening tab-style options pages

chrome/browser/resources/md_extensions/item.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.
 
 cr.define('extensions', function() {
   /** @interface */
   var ItemDelegate = function() {};
 
   ItemDelegate.prototype = {
     /** @param {string} id */
@@ skipping 23 matching lines @@
      */
     setItemAllowedOnAllSites: assertNotReached,
 
     /**
      * @param {string} id
      * @param {boolean} collectsErrors
      */
     setItemCollectsErrors: assertNotReached,
 
     /**
-     * @param {string} id,
+     * @param {string} id
      * @param {chrome.developerPrivate.ExtensionView} view
      */
     inspectItemView: assertNotReached,
 
     /** @param {string} id */
     repairItem: assertNotReached,
+
+    /** @param {string} id */
+    showItemOptionsPage: assertNotReached,
   };
 
   var Item = Polymer({
     is: 'extensions-item',
 
     behaviors: [I18nBehavior],
 
     properties: {
       // The item's delegate, or null.
       delegate: {
@@ skipping 153 matching lines @@
       return this.data.blacklistText ? 'severe' : 'mild';
     },
   });
 
   return {
     Item: Item,
     ItemDelegate: ItemDelegate,
   };
 });