To support non-default values of scale_resolution_down_by. Bug: webrtc:10069 Change-Id: I7efb39cc06a895986f9583acc2180245c009a7fa Reviewed-on: https://webrtc-review.googlesource.com/c/121650 Commit-Queue: Mirta Dvornicic <mirtad@webrtc.org> Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26677}