Add unit tests for the 'disable-sync' flag

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': [
       '../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',
       '../components/autofill/content/renderer/test_password_generation_agent.h',
@@ skipping 265 matching lines @@
       'browser/sync/glue/sync_backend_host_mock.h',
       'browser/sync/glue/sync_backend_registrar_unittest.cc',
       'browser/sync/glue/synced_session_tracker_unittest.cc',
       'browser/sync/glue/typed_url_model_associator_unittest.cc',
       'browser/sync/glue/ui_model_worker_unittest.cc',
       'browser/sync/profile_sync_auth_provider_unittest.cc',
       'browser/sync/profile_sync_components_factory_impl_unittest.cc',
       'browser/sync/profile_sync_service_android_unittest.cc',
       'browser/sync/profile_sync_service_autofill_unittest.cc',
       'browser/sync/profile_sync_service_bookmark_unittest.cc',
+      'browser/sync/profile_sync_service_factory_unittest.cc',
       'browser/sync/profile_sync_service_startup_unittest.cc',
       'browser/sync/profile_sync_service_typed_url_unittest.cc',
       'browser/sync/profile_sync_service_unittest.cc',
       'browser/sync/profile_sync_test_util.cc',
       'browser/sync/profile_sync_test_util.h',
       'browser/sync/sessions/session_data_type_controller_unittest.cc',
       'browser/sync/sessions/tab_node_pool_unittest.cc',
       'browser/sync/startup_controller_unittest.cc',
       'browser/sync/sync_startup_tracker_unittest.cc',
       'browser/sync/test/test_http_bridge_factory.cc',
@@ skipping 2438 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }