nsIURI* url = nsnull; rv = nsComponentManager::CreateInstance( kSimpleURICID, nsnull, NS_GET_IID(nsIURI), (void**) &url);
nsIURI* url; rv = CallCreateInstance(kSimpleURICID, &url);
NS_IMETHODIMP GeckoProtocolHandlerImpl::NewURI(const nsACString & aSpec, const char *aOriginCharset, nsIURI *aBaseURI, nsIURI **_retval){    nsresult rv;    nsIURI* url = nsnull;    rv = nsComponentManager::CreateInstance(        kSimpleURICID, nsnull, NS_GET_IID(nsIURI), (void**) &url);    if (NS_FAILED(rv))        return rv;    rv = url->SetSpec(aSpec);    if (NS_FAILED(rv))    {        NS_RELEASE(url);        return rv;    }    *_retval = url;    return rv;}