This prepares for an upcoming CL removing cross traffic processing
when it's not used.
Bug: webrtc:10365
Change-Id: I7f1f3998f7f38c2a627b888c3db6b0c459d8271d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/133485
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27682}