Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/wtf/ArrayBuffer.h

 /*
  * 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 86 matching lines @@
 
 PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBuffer* other)
 {
     return ArrayBuffer::create(other->data(), other->byteLength());
 }
 
 PassRefPtr<ArrayBuffer> ArrayBuffer::create(const void* source, unsigned byteLength)
 {
     ArrayBufferContents contents(byteLength, 1, ArrayBufferContents::ZeroInitialize);
     if (!contents.data())
-        return 0;
+        return nullptr;
     RefPtr<ArrayBuffer> buffer = adoptRef(new ArrayBuffer(contents));
     memcpy(buffer->data(), source, byteLength);
     return buffer.release();
 }
 
 PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBufferContents& contents)
 {
     return adoptRef(new ArrayBuffer(contents));
 }
 
 PassRefPtr<ArrayBuffer> ArrayBuffer::createUninitialized(unsigned numElements, unsigned elementByteSize)
 {
     return create(numElements, elementByteSize, ArrayBufferContents::DontInitialize);
 }
 
 PassRefPtr<ArrayBuffer> ArrayBuffer::create(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy)
 {
     ArrayBufferContents contents(numElements, elementByteSize, policy);
     if (!contents.data())
-        return 0;
+        return nullptr;
     return adoptRef(new ArrayBuffer(contents));
 }
 
 ArrayBuffer::ArrayBuffer(ArrayBufferContents& contents)
     : m_firstView(0), m_isNeutered(false)
 {
     contents.transfer(m_contents);
 }
 
 void* ArrayBuffer::data()
@@ skipping 33 matching lines @@
     if (index < 0)
         index = currentLength + index;
     return clampValue(index, 0, currentLength);
 }
 
 } // namespace WTF
 
 using WTF::ArrayBuffer;
 
 #endif // ArrayBuffer_h