Add ManagedUserSettings Sync data type.

sync/protocol/managed_user_setting_specifics.proto

Index: sync/protocol/managed_user_setting_specifics.proto
diff --git a/sync/protocol/preference_specifics.proto b/sync/protocol/managed_user_setting_specifics.proto
similarity index 63%
copy from sync/protocol/preference_specifics.proto
copy to sync/protocol/managed_user_setting_specifics.proto
index 4827c5dc20ceba8b127ce45bb52d0d7ee6f9c0d5..fcd1d964267beb42d04cd2cc67d7d9dc70191b41 100644
--- a/sync/protocol/preference_specifics.proto
+++ b/sync/protocol/managed_user_setting_specifics.proto
@@ -1,8 +1,8 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright (c) 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.
 //
-// Sync protocol datatype extension for preferences.
+// Sync protocol datatype extension for managed user settings.
 
 // Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
 // any fields in this file.
@@ -14,9 +14,8 @@ option retain_unknown_fields = true;
 
 package sync_pb;
 
-// Properties of preference sync objects.
-message PreferenceSpecifics {
+// Properties of managed user setting sync objects.
+message ManagedUserSettingSpecifics {
   optional string name = 1;
   optional string value = 2;
 }
-