GitLab

I missed the fact that you need to explicitly press the "Start Review"
button with one of my recent CL's.  I figure that there are other new
Chromium contributors who may have a similar experience -- so, updating
the checklist to explicitly call this out.

Change-Id: I96a9b97df38bd876b28bf5dc5c493baaf0f561fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2636685
Commit-Queue: Howard Wolosky <Howard.Wolosky@microsoft.com>
Reviewed-by: Toby Huang <tobyhuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845249}