Revert of https://codereview.chromium.org/93943003/
Reason for revert: We are actually going to ignore autocomplete=off behind a flag, so we need this API back. We will eventually remove this after we take away the flag.

TBR=abarth@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/108233004

git-svn-id: svn://svn.chromium.org/blink/trunk@163351 bbb929c8-8fbe-4397-9dbb-9b2b20218538