sync: Support nudges from non-blocking sync types

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 28 matching lines @@
         'test/engine/fake_sync_scheduler.cc',
         'test/engine/fake_sync_scheduler.h',
         'test/engine/injectable_sync_context_proxy.cc',
         'test/engine/injectable_sync_context_proxy.h',
         'test/engine/mock_connection_manager.cc',
         'test/engine/mock_connection_manager.h',
         'test/engine/mock_model_type_sync_proxy.cc',
         'test/engine/mock_model_type_sync_proxy.h',
         'test/engine/mock_model_type_sync_worker.cc',
         'test/engine/mock_model_type_sync_worker.h',
+        'test/engine/mock_nudge_handler.cc',
+        'test/engine/mock_nudge_handler.h',
         'test/engine/mock_update_handler.cc',
         'test/engine/mock_update_handler.h',
         'test/engine/single_type_mock_server.cc',
         'test/engine/single_type_mock_server.h',
         'test/engine/test_directory_setter_upper.cc',
         'test/engine/test_directory_setter_upper.h',
         'test/engine/test_id_factory.h',
         'test/engine/test_syncable_utils.cc',
         'test/engine/test_syncable_utils.h',
         'test/fake_encryptor.cc',
@@ skipping 564 matching lines @@
           ],
           'variables': {
             'test_suite_name': 'sync_unit_tests',
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }