[Sync] Generalize StringOrdinal to handle ordinal_in_parent field

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 2021 matching lines @@
         'common/net/gaia/gaia_oauth_client_unittest.cc',
         'common/net/gaia/google_service_auth_error_unittest.cc',
         'common/net/gaia/oauth_request_signer_unittest.cc',
         'common/net/gaia/oauth2_access_token_fetcher_unittest.cc',
         'common/net/gaia/oauth2_api_call_flow_unittest.cc',
         'common/net/gaia/oauth2_mint_token_fetcher_unittest.cc',
         'common/net/gaia/oauth2_mint_token_flow_unittest.cc',
         'common/net/gaia/oauth2_revocation_fetcher_unittest.cc',
         'common/net/x509_certificate_model_unittest.cc',
         'common/service_process_util_unittest.cc',
-        'common/string_ordinal_unittest.cc',
         'common/switch_utils_unittest.cc',
         'common/thumbnail_score_unittest.cc',
         'common/time_format_unittest.cc',
         'common/web_apps_unittest.cc',
         'common/worker_thread_ticker_unittest.cc',
         'common/zip_reader_unittest.cc',
         'common/zip_unittest.cc',
         'nacl/nacl_ipc_adapter_unittest.cc',
         'nacl/nacl_validation_query_unittest.cc',
         'renderer/chrome_content_renderer_client_unittest.cc',
@@ skipping 2699 matching lines @@
                 '--result', '<@(_outputs)',
                 '--isolate', 'browser_tests.isolate',
               ],
             },
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }