Account for time measurement variability. Bug: webrtc:10553 Change-Id: I7a82a15d5a7c2fb3e5cb80bfdf140433a3b93349 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/151780 Commit-Queue: Yves Gerey <yvesg@google.com> Reviewed-by: Artem Titov <titovartem@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29101}