Browser test for PINless authentication.

This test verifies that a PIN is required before pairing and is not required
afterwards. It then cleans up the pairing and tries again. The second run
serves to verify that the clean-up worked correctly and also allows us to
test both methods of clearing a pairing.

Review URL: https://codereview.chromium.org/38903002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230839 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230839