JS cleanup for cr_elements

ui/webui/resources/cr_elements/cr_dropdown_menu/cr_dropdown_menu.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. */
+// 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
- * 'cr-dropdown-menu' is a Chrome-specific wrapper around paper-dropdown-menu.
+ * `cr-dropdown-menu` is a Chrome-specific wrapper around paper-dropdown-menu.

[stevenjb, 2015/03/06 17:39:15]

Is this a Polymer convention or a Closure one? I don't see any any reference to
using backquote in the style guide.

[michaelpg, 2015/03/06 18:24:09]

Polymer. The core-doc-viewer will format this as code (monospace),
markdown-style.

But it's not important; we aren't even sure we'll use core-doc-viewer and if it
needs to be changed it's fairly trivial to do so in the future instead of now.

  * It includes a paper-dropdown so its content should just be a core-menu and
  * items.
  *
  * Example:
  *   <cr-dropdown-menu>
  *     <core-menu>
  *       <paper-item>Chrome</paper-item>
  *       <paper-item>Firefox</paper-item>
  *       <paper-item>IE</paper-item>
  *       <paper-item>Opera</paper-item>
@@ skipping 25 matching lines @@
     label: '<Dropdown Menu Label>',
   },
 
   /** @override */
   domReady: function() {
     assert(
         this.querySelector('.menu'),
         'cr-dropdown-menu must have a menu child with class="menu".');
   },
 });