GitLab

Add two finch flags to collect synthetic trial data for enable/tracking-
only group that users has "seen" the homepage promo.

Bug: 1068831, 1084292
Change-Id: Ibf798c0f814c215fd958af2e9463828358b23be2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2208271
Commit-Queue: Wenyu Fu <wenyufu@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773382}