Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/wtf/ArrayBufferView.cpp

 /*
  * Copyright (C) 2009 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 33 matching lines @@
 }
 
 ArrayBufferView::~ArrayBufferView()
 {
     if (m_buffer)
         m_buffer->removeView(this);
 }
 
 void ArrayBufferView::neuter()
 {
-    m_buffer = 0;
+    m_buffer = nullptr;
     m_byteOffset = 0;
 }
 
 const char* ArrayBufferView::typeName()
 {
     switch (type()) {
     case TypeInt8:
         return "Int8";
         break;
     case TypeUint8:
@@ skipping 22 matching lines @@
         break;
     case TypeDataView:
         return "DataView";
         break;
     }
     ASSERT_NOT_REACHED();
     return "Unknown";
 }
 
 }