From the spec:
If the EXT-X-INDEPENDENT-SEGMENTS tag appears in a Master
Playlist, it applies to every Media Segment in every Media
Playlist in the Master Playlist.
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This requires propagation of attributes from the master
playlist to the media playlists. This CL only includes
independent segments, but other inheritable attributes
will be supported in following changes. Other inheritable
attributes include variable substitution definitions and
session keys.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=202628422
