Fix for default value of FetchEvent.cancellable

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"
 #include "modules/serviceworkers/ExtendableEvent.h"
 #include "modules/serviceworkers/FetchEventInit.h"
 #include "modules/serviceworkers/RespondWithObserver.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class ExceptionState;
 class Request;
 class RespondWithObserver;
 
 // A fetch event is dispatched by the client to a service worker's script
 // context. RespondWithObserver can be used to notify the client about the
 // service worker's response.
 class MODULES_EXPORT FetchEvent final : public ExtendableEvent {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtrWillBeRawPtr<FetchEvent> create();
-    static PassRefPtrWillBeRawPtr<FetchEvent> create(const AtomicString& type, FetchEventInit&);
-    static PassRefPtrWillBeRawPtr<FetchEvent> create(const AtomicString& type, FetchEventInit&, RespondWithObserver*);
+    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&);
 
     virtual 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