Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/indexeddb/IDBTransaction.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 110 matching lines @@
     // transaction abort.
     if (!m_error) {
         m_error = error;
     }
 }
 
 PassRefPtr<IDBObjectStore> IDBTransaction::objectStore(const String& name, ExceptionState& exceptionState)
 {
     if (m_state == Finished) {
         exceptionState.throwDOMException(InvalidStateError, IDBDatabase::transactionFinishedErrorMessage);
-        return 0;
+        return nullptr;
     }
 
     IDBObjectStoreMap::iterator it = m_objectStoreMap.find(name);
     if (it != m_objectStoreMap.end())
         return it->value;
 
     if (!isVersionChange() && !m_objectStoreNames.contains(name)) {
         exceptionState.throwDOMException(NotFoundError, IDBDatabase::noSuchObjectStoreErrorMessage);
-        return 0;
+        return nullptr;
     }
 
     int64_t objectStoreId = m_database->findObjectStoreId(name);
     if (objectStoreId == IDBObjectStoreMetadata::InvalidId) {
         ASSERT(isVersionChange());
         exceptionState.throwDOMException(NotFoundError, IDBDatabase::noSuchObjectStoreErrorMessage);
-        return 0;
+        return nullptr;
     }
 
     const IDBDatabaseMetadata& metadata = m_database->metadata();
 
     RefPtr<IDBObjectStore> objectStore = IDBObjectStore::create(metadata.objectStores.get(objectStoreId), this);
     objectStoreCreated(name, objectStore);
     return objectStore.release();
 }
 
 void IDBTransaction::objectStoreCreated(const String& name, PassRefPtr<IDBObjectStore> prpObjectStore)
@@ skipping 234 matching lines @@
     event->setTarget(this);
     eventQueue->enqueueEvent(event);
 }
 
 blink::WebIDBDatabase* IDBTransaction::backendDB() const
 {
     return m_database->backend();
 }
 
 } // namespace WebCore