Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/webaudio/AudioBufferSourceNode.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:
  * 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 39 matching lines @@
 // to minimize linear interpolation aliasing.
 const double MaxRate = 1024;
 
 PassRefPtr<AudioBufferSourceNode> AudioBufferSourceNode::create(AudioContext* context, float sampleRate)
 {
     return adoptRef(new AudioBufferSourceNode(context, sampleRate));
 }
 
 AudioBufferSourceNode::AudioBufferSourceNode(AudioContext* context, float sampleRate)
     : AudioScheduledSourceNode(context, sampleRate)
-    , m_buffer(0)
+    , m_buffer(nullptr)
     , m_isLooping(false)
     , m_loopStart(0)
     , m_loopEnd(0)
     , m_virtualReadIndex(0)
     , m_isGrain(false)
     , m_grainOffset(0.0)
     , m_grainDuration(DefaultGrainDuration)
     , m_lastGain(1.0)
     , m_pannerNode(0)
 {
@@ skipping 432 matching lines @@
 void AudioBufferSourceNode::finish()
 {
     clearPannerNode();
     ASSERT(!m_pannerNode);
     AudioScheduledSourceNode::finish();
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)