Allow fallback from https to http for component update checks.

components/update_client/action_update_check.cc

Index: components/update_client/action_update_check.cc
diff --git a/components/update_client/action_update_check.cc b/components/update_client/action_update_check.cc
index 9e31eb6d33d30f8aa8d43e836ee709e8a53518f9..13455f5ae7fdb9494be670a979bd476149a73daa 100644
--- a/components/update_client/action_update_check.cc
+++ b/components/update_client/action_update_check.cc
@@ -97,9 +97,12 @@ void ActionUpdateCheck::Run(UpdateContext* update_context, Callback callback) {
 
 void ActionUpdateCheck::UpdateCheckComplete(
     int error,
-    const UpdateResponse::Results& results) {
+    const UpdateResponse::Results& results,
+    int retry_after_sec) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
+  update_context_->retry_after_sec_ = retry_after_sec;
+
   if (!error)
     OnUpdateCheckSucceeded(results);
   else