Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/web/tests/CustomEventTest.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 61 matching lines @@
         EXPECT_EQ(jsEvent->ToObject()->Get(v8::String::NewFromUtf8(isolate, "detail")), v8::Boolean::New(isolate, true));
     }
 
     static PassRefPtr<TestListener> create(v8::Isolate* isolate)
     {
         return adoptRef(new TestListener(isolate));
     }
 
 private:
     TestListener(v8::Isolate* isolate)
-        : V8AbstractEventListener(false, 0, isolate)
+        : V8AbstractEventListener(false, nullptr, isolate)
     {
     }
 
     virtual v8::Local<v8::Value> callListenerFunction(ExecutionContext*, v8::Handle<v8::Value> jsevent, Event*)
     {
         ASSERT_NOT_REACHED();
         return v8::Local<v8::Value>();
     }
 };
 
@@ skipping 19 matching lines @@
     v8::HandleScope handleScope(isolate);
     customEvent.initCustomEvent("blah", false, false, WebSerializedScriptValue::serialize(v8::Boolean::New(isolate, true)));
     RefPtr<EventListener> listener = TestListener::create(isolate);
     frame->frame()->document()->addEventListener("blah", listener, false);
     frame->frame()->document()->dispatchEvent(event);
 
     Platform::current()->unitTestSupport()->unregisterAllMockedURLs();
 }
 
 }