Implement CUP signing in UpdateClient.

components/component_updater/configurator_impl.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_COMPONENT_UPDATER_CONFIGURATOR_IMPL_H_
 #define COMPONENTS_COMPONENT_UPDATER_CONFIGURATOR_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 63 matching lines @@
   // The source of contexts for all the url requests.
   net::URLRequestContextGetter* RequestContext() const;
 
   // True means that this client can handle delta updates.
   bool DeltasEnabled() const;
 
   // True means that the background downloader can be used for downloading
   // non on-demand components.
   bool UseBackgroundDownloader() const;
 
+  // True if signing of update checks is enabled.
+  bool UseCupSigning() const;
+
  private:
   net::URLRequestContextGetter* url_request_getter_;
   std::string extra_info_;
   GURL url_source_override_;
   bool fast_update_;
   bool pings_enabled_;
   bool deltas_enabled_;
   bool background_downloads_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(ConfiguratorImpl);
 };
 
 }  // namespace component_updater
 
 #endif  // COMPONENTS_COMPONENT_UPDATER_CONFIGURATOR_IMPL_H_