Service Worker: Correct Web IDL of FetchEvent.respondWith method.

Source/modules/serviceworkers/FetchEvent.h

 // Copyright 2014 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.
 
 #ifndef FetchEvent_h
 #define FetchEvent_h
 
 #include "modules/EventModules.h"
 #include "modules/ModulesExport.h"
 #include "modules/fetch/Request.h"
@@ skipping 14 matching lines @@
 class MODULES_EXPORT FetchEvent final : public ExtendableEvent {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtrWillBeRawPtr<FetchEvent> create();
     static PassRefPtrWillBeRawPtr<FetchEvent> create(const AtomicString& type, const FetchEventInit&);
     static PassRefPtrWillBeRawPtr<FetchEvent> create(const AtomicString& type, const FetchEventInit&, RespondWithObserver*);
 
     Request* request() const;
     bool isReload() const;
 
-    void respondWith(ScriptState*, const ScriptValue&, ExceptionState&);
+    void respondWith(ScriptState*, ScriptPromise&, ExceptionState&);
 
     const AtomicString& interfaceName() const override;
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     FetchEvent();
     FetchEvent(const AtomicString& type, const FetchEventInit&, RespondWithObserver*);
 
 private:
     PersistentWillBeMember<RespondWithObserver> m_observer;
     PersistentWillBeMember<Request> m_request;
     bool m_isReload;
 };
 
 } // namespace blink
 
 #endif // FetchEvent_h