NonStandardGroupId is no longer wired up to Chrome, but if we did want to only expose certain metrics if a field trial was enabled then the right place to do that would be in blink, where WebIDL lives. This was only used prior to the WebRtcStatsReportIdl launch and experiments haven't been active in several years so its dead code. Blocked on: - https://chromium-review.googlesource.com/c/chromium/src/+/4514754 Bug: webrtc:15162 Change-Id: Ia41a4d21d7e5f029ddb121183fbd69ae7f98fac4 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/304720 Commit-Queue: Henrik Boström <hbos@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Cr-Commit-Position: refs/heads/main@{#40132}