This code does not exist in upstream webrtc.org, but based upon the headers in the files, it once did. Rather than restoring it each time we pull from upstream webrtc.org, we should move it elsewhere in tree. It appears to be used by dom/media/systemservices/VideoEngine.cpp, so that seems like the logical place to put it. We should also take the opportunity to see if we can switch to supported interfaces for accessing video / desktop capture rather than relying on code that has been undeleted from upstream.

Historically this code was part of webrtc.org but has since been removed from upstream. Rather than maintaining it as a local diff against upstream, we should just move it to where it is used.

Depends on D13092

Depends on D13094

Depends on D13095

Phabricator choked on the size of the json update patch and I had to manually split it into two.

Pushed by dminor@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/0fd399c6caab Move video_engine from webrtc to systemservices; r=pehrsons https://hg.mozilla.org/integration/autoland/rev/6cea864da2b6 Update gn generated json files; r=pehrsons https://hg.mozilla.org/integration/autoland/rev/cab408925a76 Update gn generated json files (part 2); r=pehrsons https://hg.mozilla.org/integration/autoland/rev/352048c07693 Regenerate moz.build files; r=pehrsons

https://hg.mozilla.org/mozilla-central/rev/0fd399c6caab https://hg.mozilla.org/mozilla-central/rev/6cea864da2b6 https://hg.mozilla.org/mozilla-central/rev/cab408925a76 https://hg.mozilla.org/mozilla-central/rev/352048c07693