Useful for when creating aggregate stats objects, seems like an oversight that we don't have it already. Bug: None Change-Id: Ied36afd2122464a81c7d725825353f9af59fe632 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/376220 Auto-Submit: Henrik Boström <hbos@webrtc.org> Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org> Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Cr-Commit-Position: refs/heads/main@{#43844}