Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/platform/fonts/FontFallbackList.cpp

 /*
  * Copyright (C) 2006 Apple Computer, 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 22 matching lines @@
 #include "platform/fonts/FontCache.h"
 #include "platform/fonts/FontDescription.h"
 #include "platform/fonts/FontFamily.h"
 #include "platform/fonts/SegmentedFontData.h"
 
 namespace WebCore {
 
 FontFallbackList::FontFallbackList()
     : m_pageZero(0)
     , m_cachedPrimarySimpleFontData(0)
-    , m_fontSelector(0)
+    , m_fontSelector(nullptr)
     , m_fontSelectorVersion(0)
     , m_familyIndex(0)
     , m_generation(FontCache::fontCache()->generation())
     , m_pitch(UnknownPitch)
     , m_loadingCustomFonts(false)
 {
 }
 
 void FontFallbackList::invalidate(PassRefPtr<FontSelector> fontSelector)
 {
@@ skipping 142 matching lines @@
     RefPtr<FontData> result = getFontData(fontDescription, m_familyIndex);
     if (result) {
         m_fontList.append(result);
         if (result->isLoading())
             m_loadingCustomFonts = true;
     }
     return result.get();
 }
 
 }