sync: Add helper class for P2P invalidations

chrome/chrome_tests.gypi

 # Copyright 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' : {
     'chromedriver_unittest_sources': [
       'test/chromedriver/capabilities_unittest.cc',
       'test/chromedriver/chrome/chrome_finder_unittest.cc',
       'test/chromedriver/chrome/console_logger_unittest.cc',
       'test/chromedriver/chrome/device_manager_unittest.cc',
@@ skipping 2382 matching lines @@
         'browser/sync/test/integration/dictionary_helper.cc',
         'browser/sync/test/integration/dictionary_helper.h',
         'browser/sync/test/integration/dictionary_load_observer.cc',
         'browser/sync/test/integration/dictionary_load_observer.h',
         'browser/sync/test/integration/extension_settings_helper.cc',
         'browser/sync/test/integration/extension_settings_helper.h',
         'browser/sync/test/integration/extensions_helper.cc',
         'browser/sync/test/integration/extensions_helper.h',
         'browser/sync/test/integration/passwords_helper.cc',
         'browser/sync/test/integration/passwords_helper.h',
+        'browser/sync/test/integration/p2p_invalidation_forwarder.cc',
+        'browser/sync/test/integration/p2p_invalidation_forwarder.h',
         'browser/sync/test/integration/preferences_helper.cc',
         'browser/sync/test/integration/preferences_helper.h',
         'browser/sync/test/integration/profile_sync_service_harness.cc',
         'browser/sync/test/integration/profile_sync_service_harness.h',
         'browser/sync/test/integration/retry_verifier.cc',
         'browser/sync/test/integration/retry_verifier.h',
         'browser/sync/test/integration/search_engines_helper.cc',
         'browser/sync/test/integration/search_engines_helper.h',
         'browser/sync/test/integration/sessions_helper.cc',
         'browser/sync/test/integration/sessions_helper.h',
@@ skipping 814 matching lines @@
             'utility',
           ],
           'sources': [
             'tools/service_discovery_sniffer/service_discovery_sniffer.h',
             'tools/service_discovery_sniffer/service_discovery_sniffer.cc',
           ],
         }]
     }],
   ],  # 'conditions'
 }