GitLab

For legacy reasons, there are many places that are manually drawing rounded
corners in the message center, which can all be replaced by the fast rounded
corner implementation in the bubble widget.

Change-Id: Ife0d8f3fc74a059129cae1cd85c5bbea5ee8a2bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1992016Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
Commit-Queue: Tim Song <tengs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#729989}