Refactor out a new class for syncing field trials in child processes.

chrome/chrome_common.gypi

 # Copyright (c) 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.
 
 {
   'variables': {
     # File lists shared with GN build.
     'chrome_common_sources': [
       'common/all_messages.h',
       'common/attrition_experiments.h',
@@ skipping 84 matching lines @@
       'common/switch_utils.h',
       'common/trace_event_args_whitelist.cc',
       'common/trace_event_args_whitelist.h',
       'common/tts_messages.h',
       'common/tts_utterance_request.cc',
       'common/tts_utterance_request.h',
       'common/url_constants.cc',
       'common/url_constants.h',
       'common/v8_breakpad_support_win.cc',
       'common/v8_breakpad_support_win.h',
+      'common/variations/child_process_field_trial_syncer.cc',
+      'common/variations/child_process_field_trial_syncer.h',
       'common/variations/variations_util.cc',
       'common/variations/variations_util.h',
       'common/web_application_info.cc',
       'common/web_application_info.h',
       'common/widevine_cdm_constants.cc',
       'common/widevine_cdm_constants.h',
     ],
     'chrome_common_extensions_sources': [
       'common/cast_messages.cc',
       'common/cast_messages.h',
@@ skipping 564 matching lines @@
           ],
           'dependencies': [
             'installer_util',
             '../base/base.gyp:base',
           ],
         },
       ],
     }],
   ],
 }