Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/fileapi/FileReader.cpp

 /*
  * Copyright (C) 2010 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 206 matching lines @@
     // If multiple concurrent read methods are called on the same FileReader, InvalidStateError should be thrown when the state is LOADING.
     if (m_state == LOADING) {
         exceptionState.throwDOMException(InvalidStateError, "The object is already busy reading Blobs.");
         return;
     }
 
     m_blob = blob;
     m_readType = type;
     m_state = LOADING;
     m_loadingState = LoadingStatePending;
-    m_error = 0;
+    m_error = nullptr;
     throttlingController()->pushReader(this);
 }
 
 void FileReader::executePendingRead()
 {
     ASSERT(m_loadingState == LoadingStatePending);
     m_loadingState = LoadingStateLoading;
 
     m_loader = adoptPtr(new FileReaderLoader(m_readType, this));
     m_loader->setEncoding(m_encoding);
@@ skipping 120 matching lines @@
 
 ThreadSpecific<FileReader::ThrottlingController>& FileReader::throttlingController()
 {
     AtomicallyInitializedStatic(ThreadSpecific<FileReader::ThrottlingController>*, controller = new ThreadSpecific<FileReader::ThrottlingController>);
     return *controller;
 }
 
 PassRefPtr<ArrayBuffer> FileReader::arrayBufferResult() const
 {
     if (!m_loader || m_error)
-        return 0;
+        return nullptr;
     return m_loader->arrayBufferResult();
 }
 
 String FileReader::stringResult()
 {
     if (!m_loader || m_error)
         return String();
     return m_loader->stringResult();
 }
 
 } // namespace WebCore