GitLab

The conversion from ARC to native assistant left some dead code in
settings.

Bug: 960937
Test: turned assistant feature flag on and off in about:flags
Change-Id: Icb4b03aee055cfffbd9118c56661c6431debac65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1602658Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Yue Li <updowndota@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658375}