Increase the lifetime of Navigation Preload related objects.

content/browser/service_worker/service_worker_url_request_job.cc

Index: content/browser/service_worker/service_worker_url_request_job.cc
diff --git a/content/browser/service_worker/service_worker_url_request_job.cc b/content/browser/service_worker/service_worker_url_request_job.cc
index 77a82de84346149dd8e02194c33410b7140a8db7..f462d42b812be9bda60330ccc31e5879cc198488 100644
--- a/content/browser/service_worker/service_worker_url_request_job.cc
+++ b/content/browser/service_worker/service_worker_url_request_job.cc
@@ -565,7 +565,11 @@ void ServiceWorkerURLRequestJob::DidDispatchFetchEvent(
     ServiceWorkerFetchEventResult fetch_result,
     const ServiceWorkerResponse& response,
     const scoped_refptr<ServiceWorkerVersion>& version) {
-  fetch_dispatcher_.reset();
+  // Do not clear |fetch_dispatcher_| if it has dispached a navigation prelaod

[falken, 2017/01/18 14:24:58]

nit: dispatched

[horo, 2017/01/18 16:14:57]

Done.

+  // request to keep the mojom::URLLoader related objects in it.

[falken, 2017/01/18 14:24:58]

Ah, I see... can you add something to the comment like "because the preload
response might still need to be streamed even after calling respondWith()." If
that's correct?

[horo, 2017/01/18 16:14:57]

Yes.
Done.

+  if (!did_navigation_preload_) {
+    fetch_dispatcher_.reset();
+  }
   ServiceWorkerMetrics::RecordFetchEventStatus(IsMainResourceLoad(), status);
 
   ServiceWorkerMetrics::URLRequestJobResult result =
@@ -879,7 +883,8 @@ void ServiceWorkerURLRequestJob::RequestBodyFileSizesResolved(bool success) {
       base::Bind(&ServiceWorkerURLRequestJob::DidDispatchFetchEvent,
                  weak_factory_.GetWeakPtr())));
   worker_start_time_ = base::TimeTicks::Now();
-  fetch_dispatcher_->MaybeStartNavigationPreload(request());
+  did_navigation_preload_ =
+      fetch_dispatcher_->MaybeStartNavigationPreload(request());
   fetch_dispatcher_->Run();
 }