Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/dom/FullscreenElementStack.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 108 matching lines @@
 {
     m_fullScreenChangeEventTargetQueue.clear();
     m_fullScreenErrorEventTargetQueue.clear();
 
     if (m_fullScreenRenderer)
         setFullScreenRenderer(0);
 }
 
 void FullscreenElementStack::documentWasDisposed()
 {
-    m_fullScreenElement = 0;
+    m_fullScreenElement = nullptr;
     m_fullScreenElementStack.clear();
 }
 
 bool FullscreenElementStack::fullScreenIsAllowedForElement(Element* element) const
 {
     ASSERT(element);
     return isAttributeOnAllOwners(allowfullscreenAttr, webkitallowfullscreenAttr, element->document().ownerElement());
 }
 
 void FullscreenElementStack::requestFullScreenForElement(Element* element, unsigned short flags, FullScreenCheckType checkType)
@@ skipping 286 matching lines @@
     if (!document()->isActive())
         return;
 
     m_fullScreenElement->setContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(false);
 
     m_areKeysEnabledInFullScreen = false;
 
     if (m_fullScreenRenderer)
         m_fullScreenRenderer->unwrapRenderer();
 
-    m_fullScreenElement = 0;
+    m_fullScreenElement = nullptr;
     document()->setNeedsStyleRecalc(SubtreeStyleChange);
 
     // When webkitCancelFullScreen is called, we call webkitExitFullScreen on the topDocument(). That
     // means that the events will be queued there. So if we have no events here, start the timer on
     // the exiting document.
     Document* exitingDocument = document();
     if (m_fullScreenChangeEventTargetQueue.isEmpty() && m_fullScreenErrorEventTargetQueue.isEmpty())
         exitingDocument = document()->topDocument();
     ASSERT(exitingDocument);
     from(*exitingDocument).m_fullScreenChangeDelayTimer.startOneShot(0);
@@ skipping 120 matching lines @@
         if (!target)
             target = fullscreen->webkitCurrentFullScreenElement();
     }
 
     if (!target)
         target = doc;
     m_fullScreenChangeEventTargetQueue.append(target);
 }
 
 } // namespace WebCore