Add a Mojo example apptest that runs in mojo_shell.

mojo/mojo.gyp

 # Copyright 2013 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.
 
 {
   'target_defaults': {
     'conditions': [
       ['mojo_shell_debug_url != ""', {
         'defines': [
           'MOJO_SHELL_DEBUG=1',
@@ skipping 11 matching lines @@
   'targets': [
     {
       'target_name': 'mojo',
       'type': 'none',
       'dependencies': [
         'mojo_base.gyp:mojo_base',
         'mojo_apps_js_unittests',
         'mojo_compositor_app',
         'mojo_echo_client',
         'mojo_echo_service',
+        'mojo_example_apptests',
+        'mojo_example_service',
         'mojo_geometry_lib',
         'mojo_html_viewer',
         'mojo_js',
         'mojo_launcher',
         'mojo_native_viewport_service',
         'mojo_network_service',
         'mojo_pepper_container_app',
         'mojo_png_viewer',
         'mojo_sample_app',
         'mojo_service_manager',
@@ skipping 501 matching lines @@
             'views/views_init_internal.h',
           ],
           'defines': [
             'MOJO_VIEWS_IMPLEMENTATION',
           ],
         },
       ],
     }],
   ],
 }