Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/encoding/TextEncoder.cpp

 /*
  * Copyright (C) 2013 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 30 matching lines @@
 
 DEFINE_GC_INFO(TextEncoder);
 
 PassRefPtrWillBeRawPtr<TextEncoder> TextEncoder::create(const String& utfLabel, ExceptionState& exceptionState)
 {
     const String& encodingLabel = utfLabel.isNull() ? String("utf-8") : utfLabel;
 
     WTF::TextEncoding encoding(encodingLabel);
     if (!encoding.isValid()) {
         exceptionState.throwTypeError("The encoding label provided ('" + encodingLabel + "') is invalid.");
-        return 0;
+        return nullptr;
     }
 
     String name(encoding.name());
     if (name != "UTF-8" && name != "UTF-16LE" && name != "UTF-16BE") {
         exceptionState.throwTypeError("The encoding provided ('" + encodingLabel + "') is not one of 'utf-8', 'utf-16', or 'utf-16be'.");
-        return 0;
+        return nullptr;
     }
 
     return adoptRefWillBeNoop(new TextEncoder(encoding.name()));
 }
 
 TextEncoder::TextEncoder(const String& encoding)
     : m_encoding(encoding)
     , m_codec(newTextCodec(m_encoding))
 {
 }
@@ skipping 23 matching lines @@
     else
         result = m_codec->encode(input.characters16(), input.length(), WTF::QuestionMarksForUnencodables);
 
     const char* buffer = result.data();
     const unsigned char* unsignedBuffer = reinterpret_cast<const unsigned char*>(buffer);
 
     return Uint8Array::create(unsignedBuffer, result.length());
 }
 
 } // namespace WebCore