[Sync] Move ChangeRecord into its own file (change_record.{h,cc})

chrome/chrome.gyp

 # Copyright (c) 2011 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,
 
     'variables': {
       'version_py_path': 'tools/build/version.py',
       'version_path': 'VERSION',
@@ skipping 481 matching lines @@
       # or from compiling a stub implementation.
       'target_name': 'syncapi_core',
       'type': 'static_library',
       'sources': [
         'browser/sync/engine/syncapi_internal.cc',
         'browser/sync/engine/syncapi_internal.h',
         'browser/sync/internal_api/base_node.cc',
         'browser/sync/internal_api/base_node.h',
         'browser/sync/internal_api/base_transaction.cc',
         'browser/sync/internal_api/base_transaction.h',
+        'browser/sync/internal_api/change_record.cc',
+        'browser/sync/internal_api/change_record.h',
         'browser/sync/internal_api/change_reorder_buffer.cc',
         'browser/sync/internal_api/change_reorder_buffer.h',
         'browser/sync/internal_api/configure_reason.h',
         'browser/sync/internal_api/http_post_provider_factory.h',
         'browser/sync/internal_api/http_post_provider_interface.h',
         'browser/sync/internal_api/read_node.cc',
         'browser/sync/internal_api/read_node.h',
         'browser/sync/internal_api/read_transaction.cc',
         'browser/sync/internal_api/read_transaction.h',
         'browser/sync/internal_api/syncapi_server_connection_manager.cc',
@@ skipping 1207 matching lines @@
             'destination': '<(PRODUCT_DIR)',
             'files': [
               '<(INTERMEDIATE_DIR)/repack/chrome.pak'
             ],
           },
         ],
       }],  # targets
     }],  # OS != "mac"
   ],  # 'conditions'
 }