Add extensions code to use common updater in components/update_client/

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 <algorithm>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 174 matching lines @@
 }
 
 bool ConfiguratorImpl::DeltasEnabled() const {
   return deltas_enabled_;
 }
 
 bool ConfiguratorImpl::UseBackgroundDownloader() const {
   return background_downloads_enabled_;
 }
 
+void ConfiguratorImpl::set_enable_alt_source_url(bool enable_alt_source_url) {
+  fallback_to_alt_source_url_enabled_ = enable_alt_source_url;
+}
+
 }  // namespace component_updater