UserAgent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:62.0) Gecko/20100101 Firefox/62.0

Steps to reproduce the problem:
1. run navigator.mediaDevices.enumerateDevices
2. create method to catch ondevicechange and in that method run again navigator.mediaDevices.enumerateDevices
3. disconnect attached device, compare results of enumerateDevices

What is the expected behavior?
result of enumerateDevices should differ

What went wrong?
The results are the same

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: <Copy from: 'about:version'>  Channel: n/a
OS Version: 66.0.3359.181
Flash Version: Shockwave Flash 31.0 r0