Add sync manager classes for backup/rollback:

sync/syncable/model_type.cc

 // 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.
 
 #include "sync/internal_api/public/base/model_type.h"
 
 #include "base/strings/string_split.h"
 #include "base/values.h"
 #include "sync/protocol/app_notification_specifics.pb.h"
 #include "sync/protocol/app_setting_specifics.pb.h"
@@ skipping 420 matching lines @@
 ModelTypeSet PriorityCoreTypes() {
   syncer::ModelTypeSet result;
   result.PutAll(ControlTypes());
 
   // The following are non-control core types.
   result.Put(MANAGED_USERS);
 
   return result;
 }
 
+ModelTypeSet BackupTypes() {
+  ModelTypeSet result;
+  result.Put(BOOKMARKS);
+  result.Put(PREFERENCES);
+  result.Put(THEMES);
+  result.Put(EXTENSIONS);
+  result.Put(SEARCH_ENGINES);
+  result.Put(APPS);
+  result.Put(APP_SETTINGS);
+  result.Put(EXTENSION_SETTINGS);

[Nicolas Zea, 2014/04/14 21:36:31]

Extension settings and app settings don't need to be backed up. They only exist
if sync is enabled.

[haitaol1, 2014/04/15 00:19:06]

Per offline discussion, back them up to simulate setting up extensions using
sync on new device during rollback.

+  result.Put(PRIORITY_PREFERENCES);
+  return result;
+}
+
 const char* ModelTypeToString(ModelType model_type) {
   // This is used in serialization routines as well as for displaying debug
   // information.  Do not attempt to change these string values unless you know
   // what you're doing.
   switch (model_type) {
     case TOP_LEVEL_FOLDER:
       return "Top Level Folder";
     case UNSPECIFIED:
       return "Unspecified";
     case BOOKMARKS:
@@ skipping 589 matching lines @@
 
 bool IsRealDataType(ModelType model_type) {
   return model_type >= FIRST_REAL_MODEL_TYPE && model_type < MODEL_TYPE_COUNT;
 }
 
 bool IsActOnceDataType(ModelType model_type) {
   return model_type == HISTORY_DELETE_DIRECTIVES;
 }
 
 }  // namespace syncer