
This is a step toward retaining a back-buffer in a way that works for all MediaSource implementations. It's not possible to adjust the discardBuffer calls in ExoPlayerImplInternal to discard up to (position - backBufferDurationUs). Next steps are to: 1. Find an appropriate place to specify the back buffer value, to be passed to the discardBuffer calls. I guess the LoadControl is the appropriate place to define such values. 2. Enhance discardBuffer to support a toKeyframe argument to pass through to discardTo. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=175565363