GitLab

Add a transient notification to tell the user that the tab is successfully shared.

Bug: 941177
Change-Id: I8ede1448c9bd3a4eabea2ae234f08640abc0c1d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1518899
Commit-Queue: Tina Wang <tinazwang@chromium.org>
Reviewed-by: Jeffrey Cohen <jeffreycohen@chromium.org>
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641691}