Add unit-tests for MenuButton and simplify implementation.

remoting/remoting_test.gypi

 # Copyright 2014 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.
 
 {
   'targets': [
     # Remoting unit tests
     {
       'target_name': 'remoting_unittests',
       'type': '<(gtest_target_type)',
@@ skipping 310 matching lines @@
           'destination': '<(output_dir)/sinonjs',
           'files': [
             '../third_party/sinonjs/src/sinon.js',
             '../third_party/sinonjs/src/sinon-qunit.js',
           ],
         },
         {
           'destination': '<(output_dir)',
           'files': [
             '<@(webapp_js_files)',
-          ],
-        },
-        {
-          'destination': '<(output_dir)',
-          'files': [
-            '<@(remoting_webapp_unittest_cases)'
+            '<@(remoting_webapp_unittest_cases)',
+            '<@(remoting_webapp_unittest_additional_files)'
           ],
         },
       ],
       'actions': [
         {
           'action_name': 'Build Remoting Webapp unittest.html',
           'inputs': [
             'webapp/build-html.py',
             '<(remoting_webapp_unittest_template_main)',
             '<@(webapp_js_files)',
@@ skipping 12 matching lines @@
             # exclude list.
             '--exclude-js', '<@(remoting_webapp_unittest_exclude_files)',
             '--js', '<@(remoting_webapp_unittest_cases)',
             '--instrument-js', '<@(webapp_js_files)',
            ],
         },
       ],
     },  # end of target 'remoting_webapp_js_unittest'
   ],  # end of targets
 }