Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/bindings/v8/Dictionary.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
@@ skipping 507 matching lines @@
     value = V8MediaStream::toNativeWithTypeCheck(m_isolate, v8Value);
     return true;
 }
 
 bool Dictionary::get(const String& key, RefPtr<EventTarget>& value) const
 {
     v8::Local<v8::Value> v8Value;
     if (!getKey(key, v8Value))
         return false;
 
-    value = 0;
+    value = nullptr;
     // We need to handle a DOMWindow specially, because a DOMWindow wrapper
     // exists on a prototype chain of v8Value.
     if (v8Value->IsObject()) {
         v8::Handle<v8::Object> wrapper = v8::Handle<v8::Object>::Cast(v8Value);
         v8::Handle<v8::Object> window = wrapper->FindInstanceInPrototypeChain(V8Window::domTemplate(m_isolate, worldTypeInMainThread(m_isolate)));
         if (!window.IsEmpty()) {
             value = toWrapperTypeInfo(window)->toEventTarget(window);
             return true;
         }
     }
@@ skipping 213 matching lines @@
 {
     if (forConstructor()) {
         exceptionState().throwTypeError(detail);
     } else {
         ASSERT(!methodName().isEmpty());
         exceptionState().throwTypeError(ExceptionMessages::failedToExecute(interfaceName(), methodName(), detail));
     }
 }
 
 } // namespace WebCore