while helpful by itself, it is also a preparation
for adding unittests for (to be added) svc features of the encoder.
Bug: webrtc:11404
Change-Id: I62b0645f44579f21f228d406a206b4c01d80dd02
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/174580
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31189}
