UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/60.0.3112.113 Chrome/60.0.3112.113 Safari/537.36

Steps to reproduce the problem:
1. start chrome with --use-fake-device-for-media-stream
2. go to https://webrtc.github.io/samples/src/content/getusermedia/gum/
3. the video shown is grey-ish as shown in the attached screenshot

What is the expected behavior?
the fake device is showing a green image.

What went wrong?
unclear. Seems only to affect fake devices. The video is transmitted the right way in Firefox. Also getting a snapshot of the video onto a canvas with this code still shows a green image:
const remoteVideo = document.getElementById("gum-local");                
const canvas = document.createElement("canvas");
                canvas.width = remoteVideo.videoWidth;
                canvas.height = remoteVideo.videoHeight;
                const context = canvas.getContext("2d");
                context.drawImage(remoteVideo, 0, 0, canvas.width, canvas.height);
var img = document.createElement("img"); img.src = canvas.toDataURL(); document.body.appendChild(img);

Probably some kind of alpha channel problem.

Did this work before? Yes 60.0.3112.113

Does this work in other browsers? Yes

Chrome version: 61.0.3163.79  Channel: n/a
OS Version: 
Flash Version: Shockwave Flash 16.0 r0