title: requestFileSystem ok on Chrome, but undefined on Safari7 and mobile Chrome/Safari
body: <p>I'm trying to test the HTML5 FileReader API <code>FileReader.readAsDataURL(file)</code> on mobile but I'm running into problems. It works fine in desktop Chrome, but fails in Safari and mobile Chrome/Safari</p>
  
  <p>I'm using this line:
  <code>
     window.requestFileSystem  = window.requestFileSystem || 
                                    window.webkitRequestFileSystem
     // window.requestFileSystem is undefined on Safari and mobile
  </code></p>
  
  <p>Is there a trick or a setting that I am not using?</p>