GitLab

Adding the option for homepage promo to suppress the sign in promo when
user is not signed in.

Bug: 1068831
Change-Id: I854109c4623c47f98aab1faa34f94f2d55961474
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2252379
Commit-Queue: Wenyu Fu <wenyufu@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781109}