- Update playbackInfo duration/position/bufferedPosition in a
single place.
- Remove sampleSource variable, and remove side effects from
getSampleSource. There was actually a subtle bug where
getSampleSource wasn't called by anything where no renderers
where enabled (meaning the source never transitioned).
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125676540
