Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/html/canvas/WebGLProgram.cpp

 /*
  * Copyright (C) 2009 Apple 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 38 matching lines @@
 WebGLProgram::~WebGLProgram()
 {
     deleteObject(0);
 }
 
 void WebGLProgram::deleteObjectImpl(blink::WebGraphicsContext3D* context3d, Platform3DObject obj)
 {
     context3d->deleteProgram(obj);
     if (m_vertexShader) {
         m_vertexShader->onDetached(context3d);
-        m_vertexShader = 0;
+        m_vertexShader = nullptr;
     }
     if (m_fragmentShader) {
         m_fragmentShader->onDetached(context3d);
-        m_fragmentShader = 0;
+        m_fragmentShader = nullptr;
     }
 }
 
 unsigned WebGLProgram::numActiveAttribLocations()
 {
     cacheInfoIfNeeded();
     return m_activeAttribLocations.size();
 }
 
 GLint WebGLProgram::getActiveAttribLocation(GLuint index)
@@ skipping 65 matching lines @@
 }
 
 bool WebGLProgram::detachShader(WebGLShader* shader)
 {
     if (!shader || !shader->object())
         return false;
     switch (shader->type()) {
     case GL_VERTEX_SHADER:
         if (m_vertexShader != shader)
             return false;
-        m_vertexShader = 0;
+        m_vertexShader = nullptr;
         return true;
     case GL_FRAGMENT_SHADER:
         if (m_fragmentShader != shader)
             return false;
-        m_fragmentShader = 0;
+        m_fragmentShader = nullptr;
         return true;
     default:
         return false;
     }
 }
 
 void WebGLProgram::cacheActiveAttribLocations(blink::WebGraphicsContext3D* context3d)
 {
     m_activeAttribLocations.clear();
 
@@ skipping 20 matching lines @@
         return;
     GLint linkStatus = 0;
     context->getProgramiv(object(), GL_LINK_STATUS, &linkStatus);
     m_linkStatus = linkStatus;
     if (m_linkStatus)
         cacheActiveAttribLocations(context);
     m_infoValid = true;
 }
 
 }