Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/events/WheelEvent.cpp

 /*
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2005, 2006, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 50 matching lines @@
     ScriptWrappable::init(this);
 }
 
 WheelEvent::WheelEvent(const FloatPoint& wheelTicks, const FloatPoint& rawDelta, unsigned deltaMode,
     PassRefPtr<AbstractView> view, const IntPoint& screenLocation, const IntPoint& pageLocation,
     bool ctrlKey, bool altKey, bool shiftKey, bool metaKey, bool directionInvertedFromDevice)
     : MouseEvent(EventTypeNames::wheel,
                  true, true, view, 0, screenLocation.x(), screenLocation.y(),
                  pageLocation.x(), pageLocation.y(),
                  0, 0,
-                 ctrlKey, altKey, shiftKey, metaKey, 0, 0, 0, false)
+                 ctrlKey, altKey, shiftKey, metaKey, 0, nullptr, nullptr, false)
     , m_wheelDelta(wheelTicks.x() * TickMultiplier, wheelTicks.y() * TickMultiplier)
     , m_deltaX(-rawDelta.x())
     , m_deltaY(-rawDelta.y())
     , m_deltaZ(0)
     , m_deltaMode(deltaMode)
     , m_directionInvertedFromDevice(directionInvertedFromDevice)
 {
     ScriptWrappable::init(this);
 }
 
@@ skipping 69 matching lines @@
     return toWheelEvent(EventDispatchMediator::event());
 }
 
 bool WheelEventDispatchMediator::dispatchEvent(EventDispatcher* dispatcher) const
 {
     ASSERT(event());
     return EventDispatchMediator::dispatchEvent(dispatcher) && !event()->defaultHandled();
 }
 
 } // namespace WebCore