[Files.app] Add a test of navigation list.

BUG=none
TEST=manually tested

Review URL: https://codereview.chromium.org/25447005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226989 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226989