使用node-webkit下载文件时出错（URL中的“chrome-extension”）

I'm trying to make something like pdf downloader with node-webkit. I have an input tag for the URL with some validation code. it works just fine so far .. but when i try to put URL like this one (chrome extension://oemmndcbldboiebfnladdacbdfmadadm/I'm trying to make something like pdf downloade