[Sync] Move //sync to //components/sync.

sync/protocol/managed_user_shared_setting_specifics.proto

-// Copyright 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 managed user shared settings.
-
-// Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
-// any fields in this file.
-
-syntax = "proto2";
-
-option optimize_for = LITE_RUNTIME;
-option retain_unknown_fields = true;
-
-package sync_pb;
-
-// Properties of managed user shared setting sync objects.
-message ManagedUserSharedSettingSpecifics {
-  // The MU ID for the managed user to whom the setting applies.
-  optional string mu_id = 1;
-  // The key of the setting.
-  optional string key = 2;
-  // The setting value. The setting is a JSON encoding of an arbitrary
-  // Javascript value.
-  optional string value = 3;
-  // This flag is set by the server to acknowledge that it has committed a
-  // change to a setting.
-  optional bool acknowledged = 4 [default = false];
-}