Introduce FetchEventPreloadHandle to pass the preload response to FetchEvent.

content/browser/service_worker/service_worker_fetch_dispatcher.h

Index: content/browser/service_worker/service_worker_fetch_dispatcher.h
diff --git a/content/browser/service_worker/service_worker_fetch_dispatcher.h b/content/browser/service_worker/service_worker_fetch_dispatcher.h
index 0011f475ca695ba54256119eeb8898664ca168f8..3d32ce39b79c2e463d71e2dd3919263c21bfa80a 100644
--- a/content/browser/service_worker/service_worker_fetch_dispatcher.h
+++ b/content/browser/service_worker/service_worker_fetch_dispatcher.h
@@ -10,11 +10,16 @@
 #include "base/memory/weak_ptr.h"
 #include "content/browser/service_worker/service_worker_metrics.h"
 #include "content/common/content_export.h"
+#include "content/common/service_worker/fetch_event_dispatcher.mojom.h"
 #include "content/common/service_worker/service_worker_status_code.h"
 #include "content/common/service_worker/service_worker_types.h"
 #include "content/public/common/resource_type.h"
 #include "net/log/net_log_with_source.h"
 
+namespace net {
+class URLRequest;
+}  // namespace net
+
 namespace content {
 
 class ServiceWorkerVersion;
@@ -37,6 +42,10 @@ class CONTENT_EXPORT ServiceWorkerFetchDispatcher {
       const FetchCallback& fetch_callback);
   ~ServiceWorkerFetchDispatcher();
 
+  // If appropriate, starts the navigation preload request and creates
+  // |preload_handle_|.
+  void MaybeStartNavigationPreload(net::URLRequest* original_request);
+
   // Dispatches a fetch event to the |version| given in ctor, and fires
   // |fetch_callback| (also given in ctor) when finishes. It runs
   // |prepare_callback| as an intermediate step once the version is activated
@@ -69,6 +78,8 @@ class CONTENT_EXPORT ServiceWorkerFetchDispatcher {
   std::unique_ptr<ServiceWorkerFetchRequest> request_;
   ResourceType resource_type_;
   bool did_complete_;
+  mojom::FetchEventPreloadHandlePtr preload_handle_;
+
   base::WeakPtrFactory<ServiceWorkerFetchDispatcher> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerFetchDispatcher);