UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36

Steps to reproduce the problem:
Debug in the console as below:
   let canvas = document.createElement("canvas");
   document.body.appendChild(canvas);
   let context = canvas.getContext('2d');
   context.fillStyle = 'red';
   context.fillRect(0, 0, 10, 10);
   let stream = canvas.captureStream();
   let videoTrack = stream.getVideoTracks()[0];
   videoTrack.stop();

   let capturer = new ImageCapture(videoTrack);
   capturer.getPhotoCapabilities();
   capturer.getPhotoSettings(); 

What is the expected behavior?
Throw "InvaildStateError" error.

What went wrong?
InvaildStateError does not thrown.

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 71.0.3547.0  Channel: canary
OS Version: 10.0
Flash Version: 

According to spec: https://w3c.github.io/mediacapture-image/#dom-imagecapture-getphotocapabilities