title: How to download blob url in webview
body: <p>I'm using a web view on Android.
  When I clicked the download button,
  url : &quot;blob:http://tftpblah~.com/adljk&quot;
  But I can't download it.</p>
  <p>I searched and found that the solution is converting base64 using JavaScript.
  But it doesn't solve this problem...</p>
  <p>Please help me</p>