PlzNavigate: properly set the initiator of the navigation

content/browser/service_worker/service_worker_fetch_dispatcher.cc

Index: content/browser/service_worker/service_worker_fetch_dispatcher.cc
diff --git a/content/browser/service_worker/service_worker_fetch_dispatcher.cc b/content/browser/service_worker/service_worker_fetch_dispatcher.cc
index c074651cb42c469b58061bf9905ee12c50504dfb..12242c8e6cff26cbd72835fb498f93010179fba5 100644
--- a/content/browser/service_worker/service_worker_fetch_dispatcher.cc
+++ b/content/browser/service_worker/service_worker_fetch_dispatcher.cc
@@ -418,7 +418,10 @@ void ServiceWorkerFetchDispatcher::MaybeStartNavigationPreload(
   ResourceRequest request;
   request.method = original_request->method();
   request.url = original_request->url();
-  request.request_initiator = original_request->initiator();
+  // TODO(horo): Set first_party_for_cookies to support Same-site Cookies.
+  request.request_initiator = original_request->initiator().has_value()
+                                  ? original_request->initiator()
+                                  : url::Origin(original_request->url());
   request.referrer = GURL(original_request->referrer());
   request.referrer_policy = original_info->GetReferrerPolicy();
   request.visibility_state = original_info->GetVisibilityState();