title: HtmlImageElement - how to get image type if its src doesn't have extension
body: <p>Is it possible to get image type (gif, png, jpeg, etc.) with src like this?</p>
  
  <pre><code>&lt;img src="http://d1aviatl7dpuhg.cloudfront.net/image/url/64/aHR0cDovL3BpeGNtc2FkbWluLnBpeGFibGUuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE1LzA3L3NoYXJrLmpwZw=="&gt;
  </code></pre>
  
  <p>or created by <code>new Image()</code> constructor.</p>
  
  <p>Haven't found anything helpful in W3 specs.</p>
  
  <p>I guess that a separate "XHR get src" is sort of a solution, but maybe there is a better way?</p>
  
  <p>Update: all sorts of XRHs are failing because of CORS, so ajax won't work here.</p>