sync: Implement per-type update processing

sync/sync_core.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.
 
 {
   'include_dirs': [
     '..',
   ],
   'defines': [
     'SYNC_IMPLEMENTATION',
@@ skipping 22 matching lines @@
     'engine/apply_control_data_updates.cc',
     'engine/apply_control_data_updates.h',
     'engine/apply_updates_and_resolve_conflicts_command.cc',
     'engine/apply_updates_and_resolve_conflicts_command.h',
     'engine/backoff_delay_provider.cc',
     'engine/backoff_delay_provider.h',
     'engine/commit_util.cc',
     'engine/commit_util.h',
     'engine/commit.cc',
     'engine/commit.h',
+    'engine/sync_directory_update_handler.cc',
+    'engine/sync_directory_update_handler.h',
     'engine/sync_directory_commit_contribution.cc',
     'engine/sync_directory_commit_contribution.h',
     'engine/sync_directory_commit_contributor.cc',
     'engine/sync_directory_commit_contributor.h',
     'engine/conflict_resolver.cc',
     'engine/conflict_resolver.h',
     'engine/conflict_util.cc',
     'engine/conflict_util.h',
     'engine/download.cc',
     'engine/download.h',
     'engine/get_commit_ids.cc',
     'engine/get_commit_ids.h',
     'engine/model_changing_syncer_command.cc',
     'engine/model_changing_syncer_command.h',
     'engine/net/server_connection_manager.cc',
     'engine/net/server_connection_manager.h',
     'engine/net/url_translator.cc',
     'engine/net/url_translator.h',
     'engine/nudge_source.cc',
     'engine/nudge_source.h',
-    'engine/process_updates_command.cc',
-    'engine/process_updates_command.h',
-    'engine/store_timestamps_command.cc',
-    'engine/store_timestamps_command.h',
+    'engine/process_updates_util.cc',
+    'engine/process_updates_util.h',
     'engine/sync_engine_event.cc',
     'engine/sync_engine_event.h',
     'engine/sync_scheduler.cc',
     'engine/sync_scheduler.h',
     'engine/sync_scheduler_impl.cc',
     'engine/sync_scheduler_impl.h',
     'engine/syncer.cc',
     'engine/syncer.h',
     'engine/syncer_command.cc',
     'engine/syncer_command.h',
@@ skipping 111 matching lines @@
     'util/get_session_name_win.cc',
     'util/get_session_name_win.h',
     'util/logging.cc',
     'util/logging.h',
     'util/nigori.cc',
     'util/nigori.h',
     'util/time.cc',
     'util/time.h',
   ],
 }