The Content Security Policy directive referrer was removed from the Content Security Policy Level 2 spec., <https://w3c.github.io/webappsec-csp/2/> (Editor's Draft, 29 August 2015). It was never implemented. We should remove all the tests we have for this directive.
For completeness, the directive referrer appeared in the Content Security Policy 1.1 spec, <https://www.w3.org/TR/2014/WD-CSP11-20140211/>, was mentioned as "at-risk, and may be dropped during the CR period" in an early revision of the Content Security Policy Level 2 spec., <https://www.w3.org/TR/2014/WD-CSP2-20140703/>, and was subsequently removed in <https://www.w3.org/TR/2015/CR-CSP2-20150219/>.
Created attachment 275906 [details]
Committed r199172: <http://trac.webkit.org/changeset/199172>