ServiceWorker: Reland of bypassing SW when no fetch handler existed

content/browser/service_worker/service_worker_controllee_request_handler.cc

Index: content/browser/service_worker/service_worker_controllee_request_handler.cc
diff --git a/content/browser/service_worker/service_worker_controllee_request_handler.cc b/content/browser/service_worker/service_worker_controllee_request_handler.cc
index 9bf56fd1fd1f37d1e848cdb5154dbd82753c1261..eda30303181dcab876e8e6ab9d7746857e91e4a7 100644
--- a/content/browser/service_worker/service_worker_controllee_request_handler.cc
+++ b/content/browser/service_worker/service_worker_controllee_request_handler.cc
@@ -27,6 +27,23 @@
 
 namespace content {
 
+namespace {
+
+bool MaybeForwardToServiceWorker(ServiceWorkerURLRequestJob* job,
+                                 const ServiceWorkerVersion* version) {
+  DCHECK(job);
+  DCHECK(version);
+  if (version->has_fetch_handler()) {
+    job->ForwardToServiceWorker();
+    return true;
+  }
+
+  job->FallbackToNetworkOrRenderer();
+  return false;
+}
+
+}  // namespace
+
 ServiceWorkerControlleeRequestHandler::ServiceWorkerControlleeRequestHandler(
     base::WeakPtr<ServiceWorkerContextCore> context,
     base::WeakPtr<ServiceWorkerProviderHost> provider_host,
@@ -266,11 +283,15 @@ ServiceWorkerControlleeRequestHandler::DidLookupRegistrationForMainResource(
   ServiceWorkerMetrics::CountControlledPageLoad(
       stripped_url_, active_version->has_fetch_handler(), is_main_frame_load_);
 
-  job_->ForwardToServiceWorker();
+  bool is_forwarded =
+      MaybeForwardToServiceWorker(job_.get(), active_version.get());
+
   TRACE_EVENT_ASYNC_END2(
       "ServiceWorker",
       "ServiceWorkerControlleeRequestHandler::PrepareForMainResource",
-      job_.get(), "Status", status, "Info", "Forwarded to the ServiceWorker");
+      job_.get(), "Status", status, "Info",
+      (is_forwarded) ? "Forwarded to the ServiceWorker"
+                     : "Skipped the ServiceWorker which has no fetch handler");
 }
 
 void ServiceWorkerControlleeRequestHandler::OnVersionStatusChanged(
@@ -294,7 +315,8 @@ void ServiceWorkerControlleeRequestHandler::OnVersionStatusChanged(
 
   provider_host_->AssociateRegistration(registration,
                                         false /* notify_controllerchange */);
-  job_->ForwardToServiceWorker();
+
+  MaybeForwardToServiceWorker(job_.get(), version);
 }
 
 void ServiceWorkerControlleeRequestHandler::DidUpdateRegistration(
@@ -364,7 +386,7 @@ void ServiceWorkerControlleeRequestHandler::PrepareForSubResource() {
   DCHECK(job_.get());
   DCHECK(context_);
   DCHECK(provider_host_->active_version());
-  job_->ForwardToServiceWorker();
+  MaybeForwardToServiceWorker(job_.get(), provider_host_->active_version());
 }
 
 void ServiceWorkerControlleeRequestHandler::OnPrepareToRestart() {