title: Chrome Extension save temporary file
body: <p>I have a Chrome Extension that needs to temporarily save a few (two or three) PNG images.</p>
  
  <p>What I am currently doing is getting the image data URI, and saving this in localstorage. But I know that this is not a very good way of doing it, especially as some of the images are bigger than 5mb, and I therefore have difficulty storing them.</p>
  
  <p>I've seen a few extensions (Single File Extension, and a few others) that have the ability of "saving" a temporary file in the extension folder, but I am not sure how I can achieve this.</p>
  
  <p>Can anyone help me out?</p>