[memories][csn] Allows extracting related searches from Google SRP

Bug: 1234093
Change-Id: Ia87a3c9421f8fdf55bedadc9258ed4e5686e4606
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3064413


Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Alex Gough <ajgo@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#908706}