[Autofill Assistant] Added missing include.

Not sure how this one fell through the cracks.

Bug: 806868
Change-Id: Id94a4b8b6550aba450d32175012f4c72d1216de3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1844825
Auto-Submit: Clemens Arbesser <arbesser@google.com>
Reviewed-by: Jordan Demeulenaere <jdemeulenaere@chromium.org>
Commit-Queue: Jordan Demeulenaere <jdemeulenaere@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703631}
1 file changed