service worker: Implement NavigationPreloadManager.getState

content/browser/service_worker/service_worker_registration.h

Index: content/browser/service_worker/service_worker_registration.h
diff --git a/content/browser/service_worker/service_worker_registration.h b/content/browser/service_worker/service_worker_registration.h
index 12bd008d8c031701502ce2bbfa9a52ac2b9773a6..d332fca5fc6195ae3c97b5985ab2115097e78ab8 100644
--- a/content/browser/service_worker/service_worker_registration.h
+++ b/content/browser/service_worker/service_worker_registration.h
@@ -95,6 +95,10 @@ class CONTENT_EXPORT ServiceWorkerRegistration
     return active_version() || waiting_version();
   }
 
+  bool is_navigation_preload_enabled() const {
+    return is_navigation_preload_enabled_;
+  }
+
   ServiceWorkerVersion* GetNewestVersion() const;
 
   void AddListener(Listener* listener);