network service: Create URLLoader for service worker navigation case

content/common/service_worker/service_worker_types.h

Index: content/common/service_worker/service_worker_types.h
diff --git a/content/common/service_worker/service_worker_types.h b/content/common/service_worker/service_worker_types.h
index ea22f5c3e723508a6ac2448ee160eb3f0b6303dc..8328311a5701c3141aee2ba507c015063d46a729 100644
--- a/content/common/service_worker/service_worker_types.h
+++ b/content/common/service_worker/service_worker_types.h
@@ -283,6 +283,10 @@ struct CONTENT_EXPORT NavigationPreloadState {
   std::string header;
 };
 
+struct ResourceRequest;
+using NetworkFallbackCallback =
+    base::Callback<void(std::unique_ptr<ResourceRequest>)>;
+
 }  // namespace content
 
 #endif  // CONTENT_COMMON_SERVICE_WORKER_SERVICE_WORKER_TYPES_H_