Keep workerStart timing info over request job restarts

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 3ac742ca3d8a95c82a60c98a1d5d66292ae9f3f8..2ef8b6fa823ceb1d09b7560f006321453480e732 100644
--- a/content/browser/service_worker/service_worker_controllee_request_handler.cc
+++ b/content/browser/service_worker/service_worker_controllee_request_handler.cc
@@ -64,6 +64,11 @@ net::URLRequestJob* ServiceWorkerControlleeRequestHandler::MaybeCreateJob(
     net::URLRequest* request,
     net::NetworkDelegate* network_delegate,
     ResourceContext* resource_context) {
+  if (job_.get() && worker_start_time_.is_null()) {
+    // Save worker-start time of the first job.
+    worker_start_time_ = job_->worker_start_time();
+  }
+
   if (!context_ || !provider_host_) {
     // We can't do anything other than to fall back to network.
     job_ = NULL;
@@ -119,12 +124,17 @@ void ServiceWorkerControlleeRequestHandler::GetExtraResponseInfo(
     *was_fetched_via_service_worker = false;
     *was_fallback_required_by_service_worker = false;
     *original_url_via_service_worker = GURL();
+    *worker_start_time = worker_start_time_;
     return;
   }
   job_->GetExtraResponseInfo(
       was_fetched_via_service_worker, was_fallback_required_by_service_worker,
       original_url_via_service_worker, response_type_via_service_worker,
       worker_start_time);
+  if (!worker_start_time_.is_null()) {
+    // If we have worker start time from previous job, use it.
+    *worker_start_time = worker_start_time_;
+  }
 }
 
 void ServiceWorkerControlleeRequestHandler::PrepareForMainResource(