ScriptPromise should check the constructor paraemter.

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 "V8Response.h"
 #include "bindings/v8/ScriptFunction.h"
 #include "bindings/v8/ScriptPromise.h"
@@ skipping 63 matching lines @@
     if (m_state == Initial)
         sendResponse(nullptr);
 }
 
 void RespondWithObserver::respondWith(const ScriptValue& value)
 {
     if (m_state != Initial)
         return;
 
     m_state = Pending;
-    ScriptPromise(value).then(
+    ScriptPromise::cast(value).then(
         ThenFunction::create(this, ThenFunction::Fulfilled),
         ThenFunction::create(this, ThenFunction::Rejected));
 }
 
 void RespondWithObserver::sendResponse(PassRefPtr<Response> response)
 {
     if (!executionContext())
         return;
     ServiceWorkerGlobalScopeClient::from(executionContext())->didHandleFetchEvent(m_eventID, response);
     m_state = Done;
@@ skipping 18 matching lines @@
 }
 
 RespondWithObserver::RespondWithObserver(ExecutionContext* context, int eventID)
     : ContextLifecycleObserver(context)
     , m_eventID(eventID)
     , m_state(Initial)
 {
 }
 
 } // namespace WebCore