Previous attempt: https://codereview.webrtc.org/1882733006/. There might be some benefit of having dummy encoder/decoder available in video_loopback. Bug: webrtc:5791 Change-Id: Iec316296754178c92b18dd3cf92f67ce6aed9439 Reviewed-on: https://webrtc-review.googlesource.com/c/112596 Commit-Queue: Niels Moller <nisse@webrtc.org> Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Reviewed-by: Magnus Flodman <mflodman@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26043}