The push_back pattern results in frequent vector growth which has performance overhead. This is .5% of our server's CPU Bug: webrtc:15723 Change-Id: Ic151c81a4b49a7d48a354b75f62694bc6f9a1ee4 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/331440 Reviewed-by: Victor Boivie <boivie@webrtc.org> Commit-Queue: Daniel Collins <dpcollins@google.com> Cr-Commit-Position: refs/heads/main@{#41388}