title: Input's accept attribute doesn't recognise application/json?
body: <p>I have an application that takes a file input from the user. One of the file types that it accepts is JSON. </p>
  
  <p>File extensions in <code>input</code>'s <code>accept</code> are recognised fine in <a href="http://caniuse.com/#feat=input-file-accept" rel="noreferrer">most browsers</a> (Safari being the main outlier), so sometimes the use of the MIME type is required. For JSON, the extension works fine, but if you use the <a href="https://www.iana.org/assignments/media-types/media-types.xhtml" rel="noreferrer">correct MIME type</a>, the input defaults to "All Files" as the filter.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>Extension (.json): &lt;br&gt;
  &lt;input type="file" accept=".json"&gt;
  
  &lt;br&gt;&lt;br&gt;
  
  MIME type: (application/json): &lt;br&gt;
  &lt;input type="file" accept="application/json"&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>This only happens with JSON, for what I've been able to see. Why is that? Is the type not fully accepted yet? Is it a bug?</p>
  
  <p><strong>Edit</strong>:</p>
  
  <p>Tested on:</p>
  
  <pre class="lang-none prettyprint-override"><code>                        | First | Second |
  ------------------------|-------|--------|
  Windows 10/Chrome 61    |Success|  Fail  |
  Windows 10/Firefox 56   |Success|Success |
  OSX ElCapitan/Safari 9  | Fail  |Success |
  Windows 10/Edge 40      |Success|  Fail  |
  </code></pre>
  
  <p>After seeing it work on Firefox, I'm starting to think it's a bug on Chrome.</p>