Implement Windows GPO support for "dlpref" in component updater.

components/component_updater/configurator_impl.cc

 // Copyright 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.
 
 #include "components/component_updater/configurator_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 145 matching lines @@
 }
 
 std::string ConfiguratorImpl::GetOSLongName() const {
   return version_info::GetOSType();
 }
 
 std::string ConfiguratorImpl::ExtraRequestParams() const {
   return extra_info_;
 }
 
+std::string ConfiguratorImpl::GetDownloadPreference() const {
+  return std::string();
+}
+
 net::URLRequestContextGetter* ConfiguratorImpl::RequestContext() const {
   return url_request_getter_;
 }
 
 bool ConfiguratorImpl::DeltasEnabled() const {
   return deltas_enabled_;
 }
 
 bool ConfiguratorImpl::UseBackgroundDownloader() const {
   return background_downloads_enabled_;
 }
 
 }  // namespace component_updater