Create a field test for sync sign in promo strings.

chrome/chrome_browser.gypi

 # Copyright (c) 2011 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 3884 matching lines @@
         'browser/ui/webui/sessions_ui.cc',
         'browser/ui/webui/sessions_ui.h',
         'browser/ui/webui/shared_resources_data_source.cc',
         'browser/ui/webui/shared_resources_data_source.h',
         'browser/ui/webui/ssl_client_certificate_selector_webui.cc',
         'browser/ui/webui/ssl_client_certificate_selector_webui.h',
         'browser/ui/webui/sync_internals_ui.cc',
         'browser/ui/webui/sync_internals_ui.h',
         'browser/ui/webui/sync_promo_handler.cc',
         'browser/ui/webui/sync_promo_handler.h',
+        'browser/ui/webui/sync_promo_trial.cc',
+        'browser/ui/webui/sync_promo_trial.h',
         'browser/ui/webui/sync_promo_ui.cc',
         'browser/ui/webui/sync_promo_ui.h',
         'browser/ui/webui/sync_setup_handler.cc',
         'browser/ui/webui/sync_setup_handler.h',
         'browser/ui/webui/task_manager_dialog.cc',
         'browser/ui/webui/task_manager_dialog.h',
         'browser/ui/webui/task_manager_handler.cc',
         'browser/ui/webui/task_manager_handler.h',
         'browser/ui/webui/task_manager_ui.cc',
         'browser/ui/webui/task_manager_ui.h',
@@ skipping 1332 matching lines @@
       'type': 'static_library',
       'sources': [ 'browser/history/in_memory_url_index_cache.proto' ],
       'variables': {
         'proto_in_dir': 'browser/history',
         'proto_out_dir': 'chrome/browser/history',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }