Not sure why: http://test-results.appspot.com/dashboards/flakiness_dashboard.html#showExpectations=true&tests=http%2Ftests%2Fsecurity%2FcontentSecurityPolicy%2Fxsl-unaffected-by-style-src-1.php
It's missing an image result.
Should be fixed in http://trac.webkit.org/changeset/97440