sync: Implement per-type update processing

sync/engine/syncer.h

 // Copyright (c) 2012 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.
 
 #ifndef SYNC_ENGINE_SYNCER_H_
 #define SYNC_ENGINE_SYNCER_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 52 matching lines @@
   // Requests to download updates for the |request_types|.  For a well-behaved
   // client with a working connection to the invalidations server, this should
   // be unnecessary.  It may be invoked periodically to try to keep the client
   // in sync despite bugs or transient failures.
   virtual bool PollSyncShare(ModelTypeSet request_types,
                              sessions::SyncSession* session);
 
  private:
   void ApplyUpdates(sessions::SyncSession* session);
   bool DownloadAndApplyUpdates(
+      ModelTypeSet request_types,
       sessions::SyncSession* session,
       base::Callback<void(sync_pb::ClientToServerMessage*)> build_fn);
 
   // This function will commit batches of unsynced items to the server until the
   // number of unsynced and ready to commit items reaches zero or an error is
   // encountered.  A request to exit early will be treated as an error and will
   // abort any blocking operations.
   SyncerError BuildAndPostCommits(
       ModelTypeSet request_types,
       sessions::SyncSession* session);
@@ skipping 26 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryWithLocalEdits);
   FRIEND_TEST_ALL_PREFIXES(EntryCreatedInNewFolderTest,
                            EntryCreatedInNewFolderMidSync);
 
   DISALLOW_COPY_AND_ASSIGN(Syncer);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_SYNCER_H_