sync: Process 'control' data separately

sync/sync.gyp

Index: sync/sync.gyp
diff --git a/sync/sync.gyp b/sync/sync.gyp
index 9d4cd1fe6f5dbf060e8f0800a9568ee3a9778ceb..bc7e67fc6d46d885f51e6fe6ac22d3e9948ed4bb 100644
--- a/sync/sync.gyp
+++ b/sync/sync.gyp
@@ -43,28 +43,30 @@
         'internal_api/public/engine/sync_status.h',
         'internal_api/public/sessions/error_counters.cc',
         'internal_api/public/sessions/error_counters.h',
-        'internal_api/public/sessions/syncer_status.cc',
-        'internal_api/public/sessions/syncer_status.h',
         'internal_api/public/sessions/sync_session_snapshot.cc',
         'internal_api/public/sessions/sync_session_snapshot.h',
         'internal_api/public/sessions/sync_source_info.cc',
         'internal_api/public/sessions/sync_source_info.h',
+        'internal_api/public/sessions/syncer_status.cc',
+        'internal_api/public/sessions/syncer_status.h',
         'internal_api/public/syncable/model_type.h',
         'internal_api/public/syncable/model_type_payload_map.cc',
         'internal_api/public/syncable/model_type_payload_map.h',
         'internal_api/public/util/enum_set.h',
         'internal_api/public/util/experiments.h',
         'internal_api/public/util/immutable.h',
+        'internal_api/public/util/report_unrecoverable_error_function.h',
         'internal_api/public/util/syncer_error.cc',
         'internal_api/public/util/syncer_error.h',
-        'internal_api/public/util/report_unrecoverable_error_function.h',
         'internal_api/public/util/unrecoverable_error_handler.h',
-        'internal_api/public/util/unrecoverable_error_info.h',
         'internal_api/public/util/unrecoverable_error_info.cc',
+        'internal_api/public/util/unrecoverable_error_info.h',
         'internal_api/public/util/weak_handle.cc',
         'internal_api/public/util/weak_handle.h',
         'engine/all_status.cc',
         'engine/all_status.h',
+        'engine/apply_control_data_updates.cc',
+        'engine/apply_control_data_updates.h',
         'engine/apply_updates_command.cc',
         'engine/apply_updates_command.h',
         'engine/build_commit_command.cc',
@@ -414,6 +416,8 @@
         'test/sessions/test_scoped_session_event_listener.h',
         'test/test_directory_backing_store.cc',
         'test/test_directory_backing_store.h',
+        'test/test_entry_factory.cc',
+        'test/test_entry_factory.h',
         'util/test_unrecoverable_error_handler.cc',
         'util/test_unrecoverable_error_handler.h',
       ],
@@ -529,6 +533,7 @@
           'internal_api/public/util/enum_set_unittest.cc',
           'internal_api/public/util/immutable_unittest.cc',
           'engine/apply_updates_command_unittest.cc',
+          'engine/apply_control_data_updates_unittest.cc',
           'engine/build_commit_command_unittest.cc',
           'engine/cleanup_disabled_types_command_unittest.cc',
           'engine/download_updates_command_unittest.cc',