Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/indexeddb/IDBOpenDBRequest.cpp

Index: Source/modules/indexeddb/IDBOpenDBRequest.cpp
diff --git a/Source/modules/indexeddb/IDBOpenDBRequest.cpp b/Source/modules/indexeddb/IDBOpenDBRequest.cpp
index fa8d5cc6f1297df661dec15a597b3dc140c4b1a0..9199f717a3d114ba0583a0c1f82f20c84defef3b 100644
--- a/Source/modules/indexeddb/IDBOpenDBRequest.cpp
+++ b/Source/modules/indexeddb/IDBOpenDBRequest.cpp
@@ -150,7 +150,7 @@ bool IDBOpenDBRequest::dispatchEvent(PassRefPtr<Event> event)
     // an "error" event should be fired instead.
     if (event->type() == EventTypeNames::success && resultAsAny()->type() == IDBAny::IDBDatabaseType && resultAsAny()->idbDatabase()->isClosePending()) {
         dequeueEvent(event.get());
-        setResult(0);
+        setResult(nullptr);
         onError(DOMError::create(AbortError, "The connection was closed."));
         return false;
     }