[status/task_scheduler] Remove slow repo update from add/delete comment.
[status/task_scheduler] Remove slow repo update from add/delete comment.

BUG=skia:5670

Change-Id: I6824ecf4d4908c21f598abf07c3f9831a73b6f7b
Reviewed-on: https://skia-review.googlesource.com/2862
Reviewed-by: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@google.com>
Reviewed-by: Ben Wagner <3ef7217be91069877d94f7907ce5479000772cd3@google.com>
Commit-Queue: Ben Wagner <3ef7217be91069877d94f7907ce5479000772cd3@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot