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

Source/modules/serviceworkers/RespondWithObserver.cpp

 // 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.
 
 #include "config.h"
 #include "modules/serviceworkers/RespondWithObserver.h"
 
 #include "bindings/core/v8/ScriptFunction.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptValue.h"
@@ skipping 114 matching lines @@
 
     if (defaultPrevented) {
         responseWasRejected(WebServiceWorkerResponseErrorDefaultPrevented);
         return;
     }
 
     ServiceWorkerGlobalScopeClient::from(executionContext())->didHandleFetchEvent(m_eventID);
     m_state = Done;
 }
 
-void RespondWithObserver::respondWith(ScriptState* scriptState, const ScriptValue& value, ExceptionState& exceptionState)
+void RespondWithObserver::respondWith(ScriptState* scriptState, ScriptPromise& scriptPromise, ExceptionState& exceptionState)
 {
     if (m_state != Initial) {
         exceptionState.throwDOMException(InvalidStateError, "The fetch event has already been responded to.");
         return;
     }
 
     m_state = Pending;
-    ScriptPromise::cast(scriptState, value).then(
+    scriptPromise.then(
         ThenFunction::createFunction(scriptState, this, ThenFunction::Fulfilled),
         ThenFunction::createFunction(scriptState, this, ThenFunction::Rejected));
 }
 
 void RespondWithObserver::responseWasRejected(WebServiceWorkerResponseError error)
 {
     ASSERT(executionContext());
     executionContext()->addConsoleMessage(ConsoleMessage::create(JSMessageSource, WarningMessageLevel, getMessageForResponseError(error, m_requestURL)));
 
     // The default value of WebServiceWorkerResponse's status is 0, which maps
@@ skipping 68 matching lines @@
     , m_state(Initial)
 {
 }
 
 DEFINE_TRACE(RespondWithObserver)
 {
     ContextLifecycleObserver::trace(visitor);
 }
 
 } // namespace blink