Add Mojo unit tests.

scripts/slave/recipes/chromium_trybot.py

 # 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.
 
 DEPS = [
   'chromium',
   'gclient',
   'itertools',
   'json',
   'path',
@@ skipping 15 matching lines @@
   'cc_unittests',
   'chromedriver_unittests',
   'components_unittests',
   'content_unittests',
   'crypto_unittests',
   'google_apis_unittests',
   'gpu_unittests',
   'ipc_tests',
   'jingle_unittests',
   'media_unittests',
+  'mojo_common_unittests',
+  'mojo_public_unittests',
+  'mojo_shell_unittests',
+  'mojo_system_unittests',
   'net_unittests',
   'ppapi_unittests',
   'printing_unittests',
   'remoting_unittests',
   'sql_unittests',
   'sync_unit_tests',
   'ui_unittests',
   'unit_tests',
 
   # Large tests. Sort alphabetically.
@@ skipping 319 matching lines @@
                                                    api.json.output(None))
   yield invalid_json_without_patch_test
 
   for step in ('gclient revert', 'gclient runhooks', 'compile'):
     yield (
       api.test(step.replace(' ', '_') + '_failure') +
       props() +
       api.platform.name('win') +
       api.step_data(step, retcode=1)
     )