Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/serviceworkers/WaitUntilObserver.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/serviceworkers/WaitUntilObserver.h"
 
 #include "bindings/v8/ScriptFunction.h"
 #include "bindings/v8/ScriptPromise.h"
 #include "bindings/v8/ScriptValue.h"
@@ skipping 26 matching lines @@
     {
     }
 
     virtual ScriptValue call(ScriptValue value) OVERRIDE
     {
         ASSERT(m_observer);
         ASSERT(m_resolveType == Fulfilled || m_resolveType == Rejected);
         if (m_resolveType == Rejected)
             m_observer->reportError(value);
         m_observer->decrementPendingActivity();
-        m_observer = 0;
+        m_observer = nullptr;
         return value;
     }
 
     RefPtr<WaitUntilObserver> m_observer;
     ResolveType m_resolveType;
 };
 
 PassRefPtr<WaitUntilObserver> WaitUntilObserver::create(ExecutionContext* context, int eventID)
 {
     return adoptRef(new WaitUntilObserver(context, eventID));
@@ skipping 44 matching lines @@
 {
     ASSERT(m_pendingActivity > 0);
     if (--m_pendingActivity || !executionContext())
         return;
 
     ServiceWorkerGlobalScopeClient::from(executionContext())->didHandleInstallEvent(m_eventID);
     observeContext(0);
 }
 
 } // namespace WebCore