Add sync manager classes for backup/rollback:

sync/sync_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.
 
 {
   'targets': [
     # Test support files for the 'sync_core' target.
     {
       'target_name': 'test_support_sync_core',
       'type': 'static_library',
@@ skipping 401 matching lines @@
         ],
         'sources': [
           'internal_api/debug_info_event_listener_unittest.cc',
           'internal_api/http_bridge_unittest.cc',
           'internal_api/js_mutation_event_observer_unittest.cc',
           'internal_api/js_sync_encryption_handler_observer_unittest.cc',
           'internal_api/js_sync_manager_observer_unittest.cc',
           'internal_api/protocol_event_buffer_unittest.cc',
           'internal_api/public/change_record_unittest.cc',
           'internal_api/public/sessions/sync_session_snapshot_unittest.cc',
+          'internal_api/sync_backup_manager_unittest.cc',
           'internal_api/sync_core_proxy_unittest.cc',
           'internal_api/sync_encryption_handler_impl_unittest.cc',
-          'internal_api/sync_manager_impl_unittest.cc',
+          'internal_api/sync_manager_impl_unittest.cc',          
+          'internal_api/sync_rollback_manager_base_unittest.cc',
+          'internal_api/sync_rollback_manager_unittest.cc',
           'internal_api/syncapi_server_connection_manager_unittest.cc',
         ],
         'conditions': [
           ['OS == "ios"', {
             'sources!': [
               'internal_api/http_bridge_unittest.cc',
             ],
           }],
         ],
       },
@@ skipping 258 matching lines @@
           'variables': {
             'test_suite_name': 'sync_unit_tests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)sync_unit_tests<(SHARED_LIB_SUFFIX)',
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }