Hide printer selection element (instead of making it transparent) when printer selection is closed to remove it from tab order and a11y index.

BUG=338369

Review URL: https://codereview.chromium.org/133003008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249670 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249670