Implement CUP signing in UpdateClient.

ios/chrome/browser/component_updater/ios_component_updater_configurator.cc

Index: ios/chrome/browser/component_updater/ios_component_updater_configurator.cc
diff --git a/ios/chrome/browser/component_updater/ios_component_updater_configurator.cc b/ios/chrome/browser/component_updater/ios_component_updater_configurator.cc
index 1c1025c3cfa4d8ca2dc6fb67cc8fcd6750400a49..ea16f56f3c78a818ee270d3c965dcf38fd9c37ba 100644
--- a/ios/chrome/browser/component_updater/ios_component_updater_configurator.cc
+++ b/ios/chrome/browser/component_updater/ios_component_updater_configurator.cc
@@ -5,6 +5,7 @@
 #include "ios/chrome/browser/component_updater/ios_component_updater_configurator.h"
 
 #include <string>
+#include <vector>
 
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/version.h"
@@ -42,6 +43,7 @@ class IOSConfigurator : public update_client::Configurator {
       const override;
   bool DeltasEnabled() const override;
   bool UseBackgroundDownloader() const override;
+  bool UseCupSigning() const override;
   scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner()
       const override;
 
@@ -127,6 +129,10 @@ bool IOSConfigurator::UseBackgroundDownloader() const {
   return configurator_impl_.UseBackgroundDownloader();
 }
 
+bool IOSConfigurator::UseCupSigning() const {
+  return configurator_impl_.UseCupSigning();
+}
+
 scoped_refptr<base::SequencedTaskRunner>
 IOSConfigurator::GetSequencedTaskRunner() const {
   return web::WebThread::GetBlockingPool()