[Sync] USS: Add EntityChange.

sync/sync.gyp

 # 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': {
     'chromium_code': 1,
     # Setting these two variables allows other targets to use the
     # sync_proto_sources variable as the list of sync protocol buffer files.
     'sync_proto_sources_dir': 'protocol',
@@ skipping 59 matching lines @@
         'api/attachments/attachment.h',
         'api/attachments/attachment_id.cc',
         'api/attachments/attachment_id.h',
         'api/attachments/attachment_metadata.cc',
         'api/attachments/attachment_metadata.h',
         'api/attachments/attachment_store.cc',
         'api/attachments/attachment_store.h',
         'api/attachments/attachment_store_backend.cc',
         'api/attachments/attachment_store_backend.h',
         'api/data_batch.h',
+        'api/entity_change.cc',
+        'api/entity_change.h',
         'api/entity_data.cc',
         'api/entity_data.h',
         'api/metadata_batch.h',
         'api/metadata_changes.h',
         'api/model_type_change_processor.cc',
         'api/model_type_change_processor.h',
         'api/model_type_service.cc',
         'api/model_type_service.h',
         'api/model_type_store.cc',
         'api/model_type_store.h',
@@ skipping 467 matching lines @@
       },
       'includes': [
         '../build/protoc.gypi'
       ],
       'defines': [
         'SYNC_IMPLEMENTATION'
       ],
     },
   ],
 }