- This means DrmInitData is propagated through sample queues (i.e.
is effectively attached to every sample, so we can see when it
changes when reading from the queue).
- It also allows different DrmInitData per track, which is possible
in muxed MKV/WebM, and per Representation for DASH, although we
wont be able to seamlessly adapt in the latter case.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=121821928
