User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

Participated in a video chat with google hangouts. Ended the call and closed the tab.

Actual results:

A box pops up on the top of my screen with a firefox icon and a microphone icon. When I end the call, the firefox icon remains, hovering over my windows and never closes until I completely exit firefox.

Expected results:

Entire popup should go away when the call ends.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Because this bug's Severity is normal and has not been changed, and this bug's priority is -- (none,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

It's definitely possible something has changed on the WebRTC side to break this, but I think it makes sense to investigate this on the Site Permissions side first.

I was able to reproduce this on todays Nightly on Google Hangouts / Meet on Linux. Didn't find a specific regression range with mozregression though.
There is no exception thrown in the console unless I click the webrtc sharing indicator. Then it throws because there are no active streams in the array which webrtcUI.getActiveStreams returns here: https://searchfox.org/mozilla-central/rev/3ce874dc2703831af3e5ef3a1d216ffd08057fa5/browser/base/content/webrtcIndicator.js#142-143
The indicator disappears when I close the the parent tab (which originally launched the popup with the video call).

I believe folks are seeing this on SUMO in Firefox 77. I have tagged the SUMO support questions: #microphoneicon77 and #bug1636496

Don't know if a regression range is still required since I see that Paul already has a patch but I did found a regression between the nightly builds from 2020-01-10:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=feb7d997f96164b028c9cf57a74878095cdad0d3&tochange=12bf9dc0978e049c367ba4c22052569c3acb1e50 (not sure of the potential regressor there)

I tried to dig deeper with mozregression but I got mixed results every time so it's not reliable. Hope this helps.

Thanks for looking into this! I assume this is the regression: https://hg.mozilla.org/mozilla-central/rev/99dbe196e0a62bf13ad87b212fedfee894c8a28e#l12.329

https://hg.mozilla.org/mozilla-central/rev/1ed52478a359

The patch landed in nightly and beta is affected.
:pbz, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Verified that this is fixed in latest Firefox Beta 79.0b3 on Ubuntu 18.04 64bit.