Add device policy to disallow shutdown

chrome/chrome_tests_unit.gypi

 # Copyright 2012 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.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       '../apps/saved_files_service_unittest.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.h',
       '../components/autofill/content/renderer/test_password_generation_agent.cc',
@@ skipping 1222 matching lines @@
       'browser/ui/views/toolbar/reload_button_unittest.cc',
       'browser/ui/views/toolbar/test_toolbar_actions_bar_helper_views.cc',
       'browser/ui/views/translate/translate_bubble_view_unittest.cc',
       'browser/ui/views/validation_message_bubble_delegate_unittest.cc',
       'browser/ui/website_settings/permission_bubble_manager_unittest.cc',
       'browser/ui/website_settings/permission_menu_model_unittest.cc',
       'browser/ui/website_settings/website_settings_unittest.cc',
       'browser/ui/webui/chromeos/login/l10n_util_test_util.cc',
       'browser/ui/webui/chromeos/login/l10n_util_test_util.h',
       'browser/ui/webui/chromeos/login/l10n_util_unittest.cc',
+      'browser/ui/webui/chromeos/login/shutdown_policy_observer_unittest.cc',
       'browser/ui/webui/chromeos/login/signin_userlist_unittest.cc',
       'browser/ui/webui/fileicon_source_unittest.cc',
       'browser/ui/webui/help/version_updater_chromeos_unittest.cc',
       'browser/ui/webui/history_ui_unittest.cc',
       'browser/ui/webui/ntp/ntp_user_data_logger_unittest.cc',
       'browser/ui/webui/ntp/suggestions_combiner_unittest.cc',
       'browser/ui/webui/options/autofill_options_handler_unittest.cc',
       'browser/ui/webui/options/chromeos/cros_language_options_handler_unittest.cc',
       'browser/ui/webui/options/language_options_handler_unittest.cc',
       'browser/ui/webui/options/pepper_flash_content_settings_utils_unittest.cc',
@@ skipping 1705 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }