[MD Extensions]: Fix sidebar icons

chrome/test/data/webui/extensions/extension_sidebar_test.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 Suite of tests for extension-sidebar. */
 cr.define('extension_sidebar_tests', function() {
   /**
    * A mock delegate for the sidebar.
    * @constructor
    * @implements {extensions.SidebarDelegate}
@@ skipping 41 matching lines @@
       });
 
       setup(function() {
         sidebar = document.querySelector('extensions-manager').sidebar;
         mockDelegate = new MockDelegate();
         sidebar.setDelegate(mockDelegate);
         sidebar.setListDelegate(mockDelegate);
       });
 
       test(assert(TestNames.Layout), function() {
+        extension_test_util.testIronIcons(sidebar);
+
         var testVisible = extension_test_util.testVisible.bind(null, sidebar);
         testVisible('#load-unpacked', false);
         testVisible('#pack-extensions', false);
         testVisible('#update-now', false);
 
         sidebar.set('inDevMode', true);
         Polymer.dom.flush();
 
         testVisible('#load-unpacked', true);
         testVisible('#pack-extensions', true);
@@ skipping 24 matching lines @@
             [extensions.ShowingType.APPS]);
       });
     });
   }
 
   return {
     registerTests: registerTests,
     TestNames: TestNames,
   };
 });