Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/fetch/ImageResource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 26 matching lines @@
 #include "platform/graphics/BitmapImage.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
 ImageResource::ImageResource(const ResourceRequest& resourceRequest)
     : Resource(resourceRequest, Image)
     , m_devicePixelRatioHeaderValue(1.0)
-    , m_image(0)
+    , m_image(nullptr)
     , m_loadingMultipartContent(false)
     , m_hasDevicePixelRatioHeaderValue(false)
 {
     setStatus(Unknown);
     setCustomAcceptHeader();
 }
 
 ImageResource::ImageResource(WebCore::Image* image)
     : Resource(ResourceRequest(""), Image)
     , m_image(image)
@@ skipping 63 matching lines @@
 }
 
 bool ImageResource::isSafeToUnlock() const
 {
     return !m_image || (m_image->hasOneRef() && m_image->isBitmapImage());
 }
 
 void ImageResource::destroyDecodedDataIfPossible()
 {
     if (isSafeToUnlock() && !hasClients() && !isLoading()) {
-        m_image = 0;
+        m_image = nullptr;
         setDecodedSize(0);
     } else if (m_image && !errorOccurred()) {
         m_image->destroyDecodedData(true);
     }
 }
 
 void ImageResource::allClientsRemoved()
 {
     m_pendingContainerSizeRequests.clear();
     if (m_image && !errorOccurred())
@@ skipping 320 matching lines @@
 bool ImageResource::isAccessAllowed(SecurityOrigin* securityOrigin)
 {
     if (!image()->currentFrameHasSingleSecurityOrigin())
         return false;
     if (passesAccessControlCheck(securityOrigin))
         return true;
     return !securityOrigin->taintsCanvas(response().url());
 }
 
 } // namespace WebCore