Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/mediastream/RTCIceCandidate.cpp

 /*
  * Copyright (C) 2012 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:
  *
  * 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
@@ skipping 27 matching lines @@
 #include "core/dom/ExceptionCode.h"
 
 namespace WebCore {
 
 PassRefPtr<RTCIceCandidate> RTCIceCandidate::create(const Dictionary& dictionary, ExceptionState& exceptionState)
 {
     String candidate;
     bool ok = dictionary.get("candidate", candidate);
     if (!ok || !candidate.length()) {
         exceptionState.throwDOMException(TypeMismatchError, ExceptionMessages::incorrectPropertyType("candidate", "is not a string, or is empty."));
-        return 0;
+        return nullptr;
     }
 
     String sdpMid;
     dictionary.get("sdpMid", sdpMid);
 
     unsigned short sdpMLineIndex = 0;
     dictionary.get("sdpMLineIndex", sdpMLineIndex);
 
     return adoptRef(new RTCIceCandidate(blink::WebRTCICECandidate(candidate, sdpMid, sdpMLineIndex)));
 }
@@ skipping 23 matching lines @@
 {
     return m_webCandidate.sdpMLineIndex();
 }
 
 blink::WebRTCICECandidate RTCIceCandidate::webCandidate()
 {
     return m_webCandidate;
 }
 
 } // namespace WebCore