Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/accessibility/AXScrollView.cpp

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 85 matching lines @@
 
 void AXScrollView::updateScrollbars()
 {
     if (!m_scrollView)
         return;
 
     if (m_scrollView->horizontalScrollbar() && !m_horizontalScrollbar) {
         m_horizontalScrollbar = addChildScrollbar(m_scrollView->horizontalScrollbar());
     } else if (!m_scrollView->horizontalScrollbar() && m_horizontalScrollbar) {
         removeChildScrollbar(m_horizontalScrollbar.get());
-        m_horizontalScrollbar = 0;
+        m_horizontalScrollbar = nullptr;
     }
 
     if (m_scrollView->verticalScrollbar() && !m_verticalScrollbar) {
         m_verticalScrollbar = addChildScrollbar(m_scrollView->verticalScrollbar());
     } else if (!m_scrollView->verticalScrollbar() && m_verticalScrollbar) {
         removeChildScrollbar(m_verticalScrollbar.get());
-        m_verticalScrollbar = 0;
+        m_verticalScrollbar = nullptr;
     }
 }
 
 void AXScrollView::removeChildScrollbar(AXObject* scrollbar)
 {
     size_t pos = m_children.find(scrollbar);
     if (pos != kNotFound) {
         m_children[pos]->detachFromParent();
         m_children.remove(pos);
     }
 }
 
 AXScrollbar* AXScrollView::addChildScrollbar(Scrollbar* scrollbar)
 {
     if (!scrollbar)
         return 0;
 
     AXScrollbar* scrollBarObject = toAXScrollbar(axObjectCache()->getOrCreate(scrollbar));
     scrollBarObject->setParent(this);
     m_children.append(scrollBarObject);
     return scrollBarObject;
 }
 
 void AXScrollView::clearChildren()
 {
     AXObject::clearChildren();
-    m_verticalScrollbar = 0;
-    m_horizontalScrollbar = 0;
+    m_verticalScrollbar = nullptr;
+    m_horizontalScrollbar = nullptr;
 }
 
 bool AXScrollView::computeAccessibilityIsIgnored() const
 {
     AXObject* webArea = webAreaObject();
     if (!webArea)
         return true;
 
     return webArea->accessibilityIsIgnored();
 }
@@ skipping 81 matching lines @@
     return m_scrollView;
 }
 
 void AXScrollView::scrollTo(const IntPoint& point) const
 {
     if (m_scrollView)
         m_scrollView->setScrollPosition(point);
 }
 
 } // namespace WebCore