Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/fileapi/FileReaderSync.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 32 matching lines @@
 
 FileReaderSync::FileReaderSync()
 {
     ScriptWrappable::init(this);
 }
 
 PassRefPtr<ArrayBuffer> FileReaderSync::readAsArrayBuffer(ExecutionContext* executionContext, Blob* blob, ExceptionState& exceptionState)
 {
     if (!blob) {
         exceptionState.throwDOMException(NotFoundError, FileError::notFoundErrorMessage);
-        return 0;
+        return nullptr;
     }
 
     FileReaderLoader loader(FileReaderLoader::ReadAsArrayBuffer, 0);
     startLoading(executionContext, loader, *blob, exceptionState);
 
     return loader.arrayBufferResult();
 }
 
 String FileReaderSync::readAsBinaryString(ExecutionContext* executionContext, Blob* blob, ExceptionState& exceptionState)
 {
@@ skipping 34 matching lines @@
 }
 
 void FileReaderSync::startLoading(ExecutionContext* executionContext, FileReaderLoader& loader, const Blob& blob, ExceptionState& exceptionState)
 {
     loader.start(executionContext, blob.blobDataHandle());
     if (loader.errorCode())
         FileError::throwDOMException(exceptionState, loader.errorCode());
 }
 
 } // namespace WebCore