Make User-Section be fail-safe with regard to being hidden.

dcommit of https://codereview.chromium.org/181493002/#ps20001
(cq taking > 5 hours)

BUG=346401
TBR=bcwhite@chromium.org

Review URL: https://codereview.chromium.org/181803005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253684 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253684