Moved JsonPrefStore to use SequencedWorkerPool

chrome/chrome_tests.gypi

 # Copyright (c) 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' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
       'common/pref_names.cc',
@@ skipping 2865 matching lines @@
         'browser/chromeos/extensions/file_browser_notifications_browsertest.cc',
         'browser/chromeos/extensions/file_browser_private_apitest.cc',
         'browser/chromeos/extensions/info_private_apitest.cc',
         'browser/chromeos/extensions/power/power_api_browsertest.cc',
         'browser/chromeos/extensions/wallpaper_private_apitest.cc',
         'browser/chromeos/kiosk_mode/mock_kiosk_mode_settings.cc',
         'browser/chromeos/kiosk_mode/mock_kiosk_mode_settings.h',
         'browser/chromeos/login/enrollment/enterprise_enrollment_screen_browsertest.cc',
         'browser/chromeos/login/existing_user_controller_browsertest.cc',
         'browser/chromeos/login/login_browsertest.cc',
+        'browser/chromeos/login/login_utils_browsertest.cc',
         'browser/chromeos/login/mock_authenticator.cc',
         'browser/chromeos/login/mock_authenticator.h',
         'browser/chromeos/login/enrollment/mock_enterprise_enrollment_screen.cc',
         'browser/chromeos/login/enrollment/mock_enterprise_enrollment_screen.h',
         'browser/chromeos/login/mock_eula_screen.cc',
         'browser/chromeos/login/mock_eula_screen.h',
         'browser/chromeos/login/mock_network_screen.cc',
         'browser/chromeos/login/mock_network_screen.h',
         'browser/chromeos/login/mock_screen_observer.cc',
         'browser/chromeos/login/mock_screen_observer.h',
@@ skipping 2061 matching lines @@
             'sync_integration_tests.isolate',
           ],
           'sources': [
             'sync_integration_tests.isolate',
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }