Remove stale comments

Per comments on the bug, we seem to be satisfied with the logic, so
remove the TODO comments.

Bug: 1239270
Change-Id: I940a52fbe45d268f93fdcbf2f99776b0ff233863
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4003544


Reviewed-by: Hubert Chao <hchao@chromium.org>
Auto-Submit: David Benjamin <davidben@chromium.org>
Commit-Queue: Hubert Chao <hchao@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1282184}