Drop document.createEvent support for things still behind a flag

third_party/WebKit/Source/modules/serviceworkers/InstallEvent.h

 // Copyright 2015 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 InstallEvent_h
 #define InstallEvent_h
 
 #include "modules/EventModules.h"
 #include "modules/ModulesExport.h"
 #include "modules/serviceworkers/ExtendableEvent.h"
 #include "modules/serviceworkers/ForeignFetchOptions.h"
 
 namespace blink {
 
 class USVStringOrUSVStringSequence;
 
 class MODULES_EXPORT InstallEvent : public ExtendableEvent {
     DEFINE_WRAPPERTYPEINFO();
 
 public:
-    static InstallEvent* create();
     static InstallEvent* create(const AtomicString& type, const ExtendableEventInit&);
     static InstallEvent* create(const AtomicString& type, const ExtendableEventInit&, WaitUntilObserver*);
 
     ~InstallEvent() override;
 
     void registerForeignFetch(ExecutionContext*, const ForeignFetchOptions&, ExceptionState&);
 
     const AtomicString& interfaceName() const override;
 
 protected:
-    InstallEvent();
     InstallEvent(const AtomicString& type, const ExtendableEventInit&);
     InstallEvent(const AtomicString& type, const ExtendableEventInit&, WaitUntilObserver*);
 };
 
 } // namespace blink
 
 #endif // InstallEvent_h