sync: Introduce ModelTypeRegistry and helpers

sync/engine/process_updates_util.h

 // 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.
 
 #ifndef SYNC_ENGINE_PROCESS_UPDATES_UTIL_H_
 #define SYNC_ENGINE_PROCESS_UPDATES_UTIL_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 13 matching lines @@
 class StatusController;
 }
 
 namespace syncable {
 class ModelNeutralWriteTransaction;
 class Directory;
 }
 
 class Cryptographer;
 
-// TODO(rlarocque): Move these definitions somewhere else?
 typedef std::vector<const sync_pb::SyncEntity*> SyncEntityList;
-typedef std::map<ModelType, SyncEntityList> TypeSyncEntityMap;
-
-// Given a GetUpdates response, iterates over all the returned items and
-// divides them according to their type.  Outputs a map from model types to
-// received SyncEntities.  The output map will have entries (possibly empty)
-// for all types in |requested_types|.
-void PartitionUpdatesByType(
-    const sync_pb::GetUpdatesResponse& updates,
-    ModelTypeSet requested_types,
-    TypeSyncEntityMap* updates_by_type);
 
 // Processes all the updates associated with a single ModelType.
 void ProcessDownloadedUpdates(
     syncable::Directory* dir,
     syncable::ModelNeutralWriteTransaction* trans,
     ModelType type,
     const SyncEntityList& applicable_updates,
     sessions::StatusController* status);
 
 // Checks whether or not an update is fit for processing.
 //
 // The answer may be "no" if the update appears invalid, or it's not releveant
 // (ie. a delete for an item we've never heard of), or other reasons.
 VerifyResult VerifyUpdate(
     syncable::ModelNeutralWriteTransaction* trans,
     const sync_pb::SyncEntity& entry,
     ModelType requested_type);
 
 // If the update passes a series of checks, this function will copy
 // the SyncEntity's data into the SERVER side of the syncable::Directory.
 void ProcessUpdate(

[tim (not reviewing), 2014/01/16 18:28:22]

As far as I can tell, nothing calls this, or VerifyUpdate, except
ProcessDownloadedUpdates.  Seems like that should be the only function exposed
here?  Which overlaps somewhat with GetUpdatesProcessor, but one thing at a
time.  We can sort that out when more dust settles.

[rlarocque, 2014/01/16 20:28:42]

You're right, there's no reason to expose these here.

I've hidden them in the .cc file.

     const sync_pb::SyncEntity& proto_update,
     const Cryptographer* cryptographer,
     syncable::ModelNeutralWriteTransaction* const trans);
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_PROCESS_UPDATES_UTIL_H_