Add a datatype for supervised user whitelists.

sync/protocol/managed_user_whitelist_specifics.proto

+// 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.
+//
+// Sync protocol datatype extension for supervised user whitelists.
+
+// 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 supervised user whitelist sync objects.
+// The fields here are a subset of the fields in an ExtensionSpecifics.
+message ManagedUserWhitelistSpecifics {
+  // Globally unique id for this whitelist that identifies it in the Web Store.
+  optional string id = 1;
+
+  // The name of the whitelist.
+  optional string name = 2;
+}