Try to always show a label with autofill suggestions.

This is mostly relevant when there are duplicate suggestions.

BUG=65133
TEST=none

Review URL: http://codereview.chromium.org/5851001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@69230 0039d316-1c4b-4281-b951-d872f2087c98