Resolve preloadResponse of Navigation Preload even if the response body is empty.

content/renderer/service_worker/service_worker_context_client.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/service_worker/service_worker_context_client.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/lazy_instance.h"
@@ skipping 346 matching lines @@
     : public mojom::URLLoaderClient {
  public:
   NavigationPreloadRequest(int fetch_event_id,
                            const GURL& url,
                            mojom::FetchEventPreloadHandlePtr preload_handle)
       : fetch_event_id_(fetch_event_id),
         url_(url),
         url_loader_(std::move(preload_handle->url_loader)),
         binding_(this, std::move(preload_handle->url_loader_client_request)) {}
 
-  ~NavigationPreloadRequest() override {
-  }
+  ~NavigationPreloadRequest() override {}
 
   void OnReceiveResponse(
       const ResourceResponseHead& response_head,
       mojom::DownloadedTempFilePtr downloaded_file) override {
     DCHECK(!response_);
     DCHECK(!downloaded_file);
     response_ = base::MakeUnique<blink::WebURLResponse>();
     // TODO(horo): Set report_security_info to true when DevTools is attached.
     const bool report_security_info = false;
     WebURLLoaderImpl::PopulateURLResponse(url_, response_head, response_.get(),
@@ skipping 35 matching lines @@
     if (status.error_code != net::OK) {
       // This will delete |this|.
       ReportErrorToClient("Service Worker navigation preload network error.");
       return;
     }
 
     ServiceWorkerContextClient* client =
         ServiceWorkerContextClient::ThreadSpecificInstance();
     if (!client)
       return;
+    if (response_) {
+      // When the response body from the server is empty, OnComplete() is called
+      // without OnStartLoadingResponseBody().
+      DCHECK(!body_.is_valid());
+      client->OnNavigationPreloadResponse(fetch_event_id_, std::move(response_),
+                                          nullptr);
+    }
     // This will delete |this|.
     client->OnNavigationPreloadComplete(fetch_event_id_);
   }
 
  private:
   void MaybeReportResponseToClient() {
     if (!response_ || !body_.is_valid())
       return;
     ServiceWorkerContextClient* client =
         ServiceWorkerContextClient::ThreadSpecificInstance();
@@ skipping 1069 matching lines @@
 }
 
 base::WeakPtr<ServiceWorkerContextClient>
 ServiceWorkerContextClient::GetWeakPtr() {
   DCHECK(worker_task_runner_->RunsTasksOnCurrentThread());
   DCHECK(context_);
   return context_->weak_factory.GetWeakPtr();
 }
 
 }  // namespace content