Clean up bookmarks handling of promo row.

Bug: 1439583
Change-Id: I438bcfb565fa84177da02a467d6ecfe9209a13a9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4567619


Reviewed-by: Brandon Wylie <wylieb@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1149408}