Migrate the injectable Vp8FrameBufferControllerFactory into a settings struct, allowing for straight-forward future extensions. Bug: webrtc:11436 Change-Id: I53e555eb6ef88cf5b10ee8a43abd6ef9c930d100 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/170635 Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Reviewed-by: Sami Kalliomäki <sakal@webrtc.org> Commit-Queue: Rasmus Brandt <brandtr@webrtc.org> Cr-Commit-Position: refs/heads/master@{#30839}