title: HTML 5 Video tag not showing fullscreen button
body: <p>I am trying to get a video with the video tag to include a fullscreen option in the controls. If I insert a video into a site using the following:</p>
  
  <pre><code>&lt;video controls&gt;
      &lt;source src="filename.mp4 " type="video/mp4"&gt;
  &lt;/video&gt;
  </code></pre>
  
  <p>I do not get the full screen button.</p>
  
  <p><a href="https://i.stack.imgur.com/WXprk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WXprk.png" alt="enter image description here"></a></p>
  
  <p>Interestingly when you look at <a href="https://www.w3schools.com/html/html5_video.asp" rel="nofollow noreferrer">w3schools</a> the example on the page shows the fullscreen but when you click the <strong>Try me</strong> it does not. </p>
  
  <p><a href="https://i.stack.imgur.com/cAE5y.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cAE5y.png" alt="enter image description here"></a></p>
  
  <p>Could it be because the tag is inside an frame? Is there a way around this?</p>