Add test for tab search.

Bug: b/331312566
Change-Id: Id2c7f75d32e294d420a2f1948d87e8d369359fc8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5399456


Reviewed-by: Michael Cui <mlcui@google.com>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1278696}