Only used for output filename nowadays. Previously, it was used for selecting the codec implementation. That is now done by injecting the appropriate codec factory. Bug: webrtc:9317 Change-Id: Ia2bf28f7df165fb65410ecd1f5d646ee6604e1be Reviewed-on: https://webrtc-review.googlesource.com/c/106023 Reviewed-by: Karl Wiberg <kwiberg@webrtc.org> Commit-Queue: Rasmus Brandt <brandtr@webrtc.org> Cr-Commit-Position: refs/heads/master@{#25204}