title: Why doesn't <video> autoplay trigger "play" event?
body: <p>Why doesn't play event get triggered when the video with autoplay first starts playing after loading the page?</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-js lang-js prettyprint-override"><code>document.getElementById("vid").addEventListener('play', function, false);</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;video id="vid" src="video.mp4" type="video/mp4" autoplay&gt;&lt;/video&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>It should fire the play event I think, but doesn't. </p>
  
  <p>Is this by design? and if so, why?</p>
  
  <p>Manually pressing play works normally.</p>