sync: Introduce ModelTypeRegistry and helpers

sync/engine/commit.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_COMMIT_H_
 #define SYNC_ENGINE_COMMIT_H_
 
 #include <map>
 
 #include "base/stl_util.h"
 #include "sync/base/sync_export.h"
 #include "sync/engine/sync_directory_commit_contribution.h"
-#include "sync/engine/sync_directory_commit_contributor.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/engine/model_safe_worker.h"
 #include "sync/internal_api/public/util/syncer_error.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/util/extensions_activity.h"
 
 namespace syncer {
 
 namespace sessions {
 class StatusController;
 class SyncSession;
 }
 
+class CommitterList;
 class Syncer;
 
 // This class wraps the actions related to building and executing a single
 // commit operation.
 //
 // This class' most important responsibility is to manage the ContributionsMap.
 // This class serves as a container for those objects.  Although it would have
 // been acceptable to let this class be a dumb container object, it turns out
 // that there was no other convenient place to put the Init() and
 // PostAndProcessCommitResponse() functions.  So they ended up here.
 class SYNC_EXPORT_PRIVATE Commit {
  public:
   Commit(
       const std::map<ModelType, SyncDirectoryCommitContribution*>&
           contributions,
       const sync_pb::ClientToServerMessage& message,
       ExtensionsActivity::Records extensions_activity_buffer);
 
   // This destructor will DCHECK if CleanUp() has not been called.
   ~Commit();
 
   static Commit* Init(
       ModelTypeSet requested_types,
+      ModelTypeSet enabled_types,
       size_t max_entries,
       const std::string& account_name,
       const std::string& cache_guid,
-      CommitContributorMap* contributor_map,
+      CommitterList* committer_list,
       ExtensionsActivity* extensions_activity);
 
   SyncerError PostAndProcessResponse(
       sessions::SyncSession* session,
       sessions::StatusController* status,
       ExtensionsActivity* extensions_activity);
 
   // Cleans up state associated with this commit.  Must be called before the
   // destructor.
   void CleanUp();
 
  private:
   typedef std::map<ModelType, SyncDirectoryCommitContribution*> ContributionMap;
 
   ContributionMap contributions_;
   STLValueDeleter<ContributionMap> deleter_;
 
   sync_pb::ClientToServerMessage message_;
   sync_pb::ClientToServerResponse response_;
   ExtensionsActivity::Records extensions_activity_buffer_;
 
   // Debug only flag used to indicate if it's safe to destruct the object.
   bool cleaned_up_;
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_COMMIT_H_