A new layout test, http/tests/xmlhttprequest/basic-auth-nopassword.html, was added in http://trac.webkit.org/changeset/74609/ This test seems to need Mac-specific expectations.
Comitted http://trac.webkit.org/changeset/74627
Re-opening since it now looks like Win and Linux also need specific results following http://trac.webkit.org/changeset/74645/
Committed r74653