sync: Introduce ModelTypeRegistry and helpers

sync/engine/model_type_registry.h

Index: sync/engine/model_type_registry.h
diff --git a/sync/engine/model_type_registry.h b/sync/engine/model_type_registry.h
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index 0000000000000000000000000000000000000000..77c3177dda213ea14293cbbf929aeacef6675c04
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+++ b/sync/engine/model_type_registry.h
@@ -0,0 +1,71 @@
+// Copyright (c) 2014 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_MODEL_TYPE_REGISTRY_H_
+#define SYNC_ENGINE_MODEL_TYPE_REGISTRY_H_
+
+#include <map>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/stl_util.h"
+#include "sync/base/sync_export.h"
+#include "sync/internal_api/public/base/model_type.h"
+#include "sync/internal_api/public/engine/model_safe_worker.h"
+
+namespace syncer {
+
+class CommitterList;
+class UpdaterList;
+
+namespace syncable {
+class Directory;
+}  // namespace syncable
+
+class SyncDirectoryUpdateHandler;
+class SyncDirectoryCommitContributor;
+
+typedef std::map<ModelType, SyncDirectoryUpdateHandler*> UpdateHandlerMap;
+typedef std::map<ModelType, SyncDirectoryCommitContributor*>
+    CommitContributorMap;
+
+// Keeps track of the sets of active update handlers and commit contributors.
+class SYNC_EXPORT_PRIVATE ModelTypeRegistry {
+ public:
+  ModelTypeRegistry(
+      const std::vector<ModelSafeWorker*>& workers,
+      syncable::Directory* directory);
+  ~ModelTypeRegistry();
+
+  // Sets the set of enabled types.
+  void SetEnabledDirectoryTypes(const ModelSafeRoutingInfo& routing_info);
+
+  // Simple getters.
+  UpdateHandlerMap* update_handler_map();
+  CommitContributorMap* commit_contributor_map();
+
+ private:
+  // Classes to manage the types hooked up to receive and commit sync data.
+  UpdateHandlerMap update_handler_map_;
+  CommitContributorMap commit_contributor_map_;
+
+  // Deleter for the |update_handler_map_|.
+  STLValueDeleter<UpdateHandlerMap> update_handler_deleter_;
+
+  // Deleter for the |commit_contributor_map_|.
+  STLValueDeleter<CommitContributorMap> commit_contributor_deleter_;
+
+  // The known ModelSafeWorkers.
+  std::map<ModelSafeGroup, scoped_refptr<ModelSafeWorker> > workers_map_;
+
+  // The directory.  Not owned.
+  syncable::Directory* directory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ModelTypeRegistry);
+};
+
+}  // namespace syncer
+
+#endif // SYNC_ENGINE_MODEL_TYPE_REGISTRY_H_
+