title: Focus the camera on an object using focusMode on WebRTC
body: <p>I'm trying to get the camera to focus on an object, by using <code>focusMode</code> on the stream track received from <code>getUserMedia</code>. But after changing the property of focus mode to <code>manual</code> mode, I don't see it reflect on the stream also I could see that after applying <code>focusMode</code> constraint it stays unchanged(<code>focusMode: continuous</code>). The issue is when I capture an image, using the stream, the image is blurry because of lack of focus.</p>
  
  <p>Here is a code snippet.</p>
  
  <pre><code>
  navigator.mediaDevices.getUserMedia({ video: true })
          .then((stream) =&gt; {
            video.srcObject = stream;
            track = stream.getVideoTracks()[0];
            track.applyConstraints({
              advanced: [
                { focusMode: 'manual', focusDistance: 0.33 }
              ]
            })
          });
  
  </code></pre>
  
  <p>Does anybody have experience with getting the camera to focus using the <code>manual</code> or <code>single-shot</code> mode? Any help is appreciated.</p>