service worker: Add promise boilerplate for NavigationPreload enable/disable

third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerRegistration.h

Index: third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerRegistration.h
diff --git a/third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerRegistration.h b/third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerRegistration.h
index ac80115cab0ef09fc8eb01c620f009134a9ab630..c7a393d75567734d53cdfbaa7c1dde2c69a3ff76 100644
--- a/third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerRegistration.h
+++ b/third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerRegistration.h
@@ -26,6 +26,10 @@ class WebServiceWorkerRegistration {
       WebCallbacks<void, const WebServiceWorkerError&>;
   using WebServiceWorkerUnregistrationCallbacks =
       WebCallbacks<bool, const WebServiceWorkerError&>;
+  using WebEnableNavigationPreloadCallbacks =
+      WebCallbacks<void, const WebServiceWorkerError&>;
+  using WebDisableNavigationPreloadCallbacks =
+      WebCallbacks<void, const WebServiceWorkerError&>;
 
   // The handle interface that retains a reference to the implementation of
   // WebServiceWorkerRegistration in the embedder and is owned by
@@ -46,6 +50,9 @@ class WebServiceWorkerRegistration {
                       WebServiceWorkerUpdateCallbacks*) {}
   virtual void unregister(WebServiceWorkerProvider*,
                           WebServiceWorkerUnregistrationCallbacks*) {}
+
+  virtual void enableNavigationPreload(WebEnableNavigationPreloadCallbacks*) {}
+  virtual void disableNavigationPreload(WebEnableNavigationPreloadCallbacks*) {}
 };
 
 }  // namespace blink