else if (aIID.Equals(nsIRDFDataSource::GetIID()))
else if (aIID.Equals(NS_GET_IID(nsIRDFDataSource)))
nsXPINotifierImpl::QueryInterface(REFNSIID aIID, void** aResult){    NS_PRECONDITION(aResult != nsnull, "null ptr");    if (! aResult)        return NS_ERROR_NULL_POINTER;    static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);    if (aIID.Equals(kISupportsIID))     {        *aResult = NS_STATIC_CAST(nsISupports*, this);    }    else if (aIID.Equals(nsIRDFDataSource::GetIID()))     {        if (mInner)            return mInner->QueryInterface(aIID, aResult);    }    else if (aIID.Equals(nsIRDFXMLSinkObserver::GetIID()))     {        *aResult = NS_STATIC_CAST(nsIRDFXMLSinkObserver*, this);    }    else     {        *aResult = nsnull;        return NS_NOINTERFACE;    }    NS_ADDREF(this);    return NS_OK;}