[ServiceWorker] Handle ServiceWorker script fetch error code correctly. [chromium]

LayoutTest is here: https://codereview.chromium.org/663723002

BUG=424464
TEST=http/tests/serviceworker/registration.html

Review URL: https://codereview.chromium.org/660973002

Cr-Commit-Position: refs/heads/master@{#300079}

content/browser/service_worker/service_worker_register_job.cc

@@ -352,11 +352,8 @@ void ServiceWorkerRegisterJob::OnStartWorkerFinished(
       case net::ERR_ABORTED:
         status = SERVICE_WORKER_ERROR_ABORT;
         break;
-      case net::ERR_FAILED:
-        status = SERVICE_WORKER_ERROR_NETWORK;
-        break;
       default:
-        NOTREACHED();
+        status = SERVICE_WORKER_ERROR_NETWORK;
     }
   }
   Complete(status);

content/browser/service_worker/service_worker_write_to_cache_job.cc

@@ -128,8 +128,7 @@ bool ServiceWorkerWriteToCacheJob::ReadRawData(
 
   // No more data to process, the job is complete.
   io_buffer_ = NULL;
-  version_->script_cache_map()->NotifyFinishedCaching(
-      url_, net::URLRequestStatus());
+  version_->script_cache_map()->NotifyFinishedCaching(url_, status);
   did_notify_finished_ = true;
   return status.is_success();
 }