Remove internal uses of TrackDisplayUpdateScope in CueTimeline

Separate the interval update from the update of the active cue list by
moving the former into {add,remove}CueInternal and then calling those
where appropriate.

BUG=321654

Review URL: https://codereview.chromium.org/993563002

git-svn-id: svn://svn.chromium.org/blink/trunk@191558 bbb929c8-8fbe-4397-9dbb-9b2b20218538
2 files changed
tree: 8ab8b8d706bcd2097ce47d21d350e8ffd09e7d05
  1. third_party/