[ios] Remove reference to a deleted flag

Change-Id: I6233c993ebe53e200a0c1e883f5152cbe30b0250
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3143771


Commit-Queue: David Jean <djean@chromium.org>
Commit-Queue: Nohemi Fernandez <fernandex@chromium.org>
Auto-Submit: David Jean <djean@chromium.org>
Reviewed-by: Nohemi Fernandez <fernandex@chromium.org>
Cr-Commit-Position: refs/heads/main@{#918543}