Trivial perf optimization. Bug: None Change-Id: I0ceabc2a6aa0c52f4626c8792c17a60d2028712d Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/171694 Reviewed-by: Stefan Holmer <stefan@webrtc.org> Commit-Queue: Erik Språng <sprang@webrtc.org> Cr-Commit-Position: refs/heads/master@{#30901}