Organizing model type, notification type, root tag and model type string in map.

sync/internal_api/public/base/model_type.h

 // Copyright 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.
 
 // Enumerate the various item subtypes that are supported by sync.
 // Each sync object is expected to have an immutable object type.
 // An object's type is inferred from the type of data it holds.
 
 #ifndef SYNC_INTERNAL_API_PUBLIC_BASE_MODEL_TYPE_H_
 #define SYNC_INTERNAL_API_PUBLIC_BASE_MODEL_TYPE_H_
@@ skipping 18 matching lines @@
 class SyncEntity;
 }
 
 namespace syncer {
 
 // TODO(akalin): Move the non-exported functions in this file to a
 // private header.
 
 // A Java counterpart will be generated for this enum.
 // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.sync
+
+// |kModelTypeInfoMap| struct entries are in the same order as their definition
+// in ModelType enum. Don't forget to update the |kModelTypeInfoMap| struct in
+// model_type.cc when you make changes in ModelType enum.
 enum ModelType {
   // Object type unknown.  Objects may transition through
   // the unknown state during their initial creation, before
   // their properties are set.  After deletion, object types
   // are generally preserved.
   UNSPECIFIED,
   // A permanent folder whose children may be of mixed
   // datatypes (e.g. the "Google Chrome" folder).
   TOP_LEVEL_FOLDER,
 
@@ skipping 297 matching lines @@
 
 // Returns true if |model_type| supports ordering of sibling entries.
 SYNC_EXPORT bool TypeSupportsOrdering(ModelType model_type);
 
 // Returns set of model types that should be backed up before first sync.
 SYNC_EXPORT ModelTypeSet BackupTypes();
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_BASE_MODEL_TYPE_H_