[Sync] Fix thread-ordering-dependent NULL dereference in NewNonFrontendDTC

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 1701 matching lines @@
         'browser/sync/glue/new_non_frontend_data_type_controller_mock.h',
         'browser/sync/glue/new_non_frontend_data_type_controller_unittest.cc',
         'browser/sync/glue/non_frontend_data_type_controller_mock.cc',
         'browser/sync/glue/non_frontend_data_type_controller_mock.h',
         'browser/sync/glue/non_frontend_data_type_controller_unittest.cc',
         'browser/sync/glue/preference_data_type_controller_unittest.cc',
         'browser/sync/glue/search_engine_data_type_controller_unittest.cc',
         'browser/sync/glue/session_model_associator_unittest.cc',
         'browser/sync/glue/shared_change_processor_mock.cc',
         'browser/sync/glue/shared_change_processor_mock.h',
+        'browser/sync/glue/shared_change_processor_unittest.cc',
         'browser/sync/glue/sync_backend_host_unittest.cc',
         'browser/sync/glue/sync_backend_registrar_unittest.cc',
         'browser/sync/glue/synced_session_tracker_unittest.cc',
         'browser/sync/glue/theme_data_type_controller_unittest.cc',
         'browser/sync/glue/theme_util_unittest.cc',
         'browser/sync/glue/typed_url_model_associator_unittest.cc',
         'browser/sync/glue/ui_model_worker_unittest.cc',
         'browser/sync/profile_sync_components_factory_impl_unittest.cc',
         'browser/sync/profile_sync_components_factory_mock.cc',
         'browser/sync/profile_sync_components_factory_mock.h',
@@ skipping 2909 matching lines @@
               # Use outputs of this action as inputs for the main target build.
               # Seems as a misnomer but makes this happy on Linux (scons).
               'process_outputs_as_sources': 1,
             },
           ],  # 'actions'
         },
       ]
     }],  # 'coverage!=0'
   ],  # 'conditions'
 }