User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0 Build ID: 20170824053622 Steps to reproduce: The window list in the screen sharing popup isn't updated until closing Firefox. Tested on Windows 7. 1. Open a window to share, e.g. Calculator. 2. Go to https://mozilla.github.io/webrtc-landing/gum_test.html 3. Click on the Window button in the demo. 4. Select the Calculator window and click Allow. 5. Close the Calculator window. 6. Refresh the demo page. 7. Click on the Window button. Actual results: The Calculator window is still on the list. Expected results: The Calculator window shouldn't be on the list after it was closed. Opening the popup again and even refreshing the browser doesn't help. The list is updated only when closing Firefox. The list should update every time a window is open, closed or its title is changed. Maybe there is an event for that on Windows or Firefox might use polling.

I could not reproduce in Firefox 57 on Windows 10. Pablo, do you see the same behavior in Firefox 56/57?

I can't reproduce in Firefox 56 on Windows 7. Thanks