Use tri-state enum for the existence of Fetch Handler in ServiceWorkerVersion.

content/browser/service_worker/service_worker_register_job.cc

Index: content/browser/service_worker/service_worker_register_job.cc
diff --git a/content/browser/service_worker/service_worker_register_job.cc b/content/browser/service_worker/service_worker_register_job.cc
index 33fa4e88c28c22cff9436c65a01160aa0f4b3132..39e16a9b0417cfeb7b9598f4552afce5e9d60810 100644
--- a/content/browser/service_worker/service_worker_register_job.cc
+++ b/content/browser/service_worker/service_worker_register_job.cc
@@ -469,7 +469,10 @@ void ServiceWorkerRegisterJob::OnInstallFinished(
 
   SetPhase(STORE);
   DCHECK(!registration()->last_update_check().is_null());
-  new_version()->set_has_fetch_handler(has_fetch_handler);
+  new_version()->set_fetch_handler_existence(
+      has_fetch_handler
+          ? ServiceWorkerVersion::FetchHandlerExistence::EXISTS
+          : ServiceWorkerVersion::FetchHandlerExistence::DOES_NOT_EXIST);
   context_->storage()->StoreRegistration(
       registration(),
       new_version(),