rAc: Handle case where validation rules are not yet downloaded

Also, mark required fields regardless of whether full validation is possible.

BUG=340365
R=dbeam@chromium.org

Review URL: https://codereview.chromium.org/137223005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248799 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248799