Need to investigate. Failing the test in TestExpectations for now.
Test skipped in r172222: <http://trac.webkit.org/r172222>. Please revert after the issue has been fixed.
Mark H says this is just an artifact of the new for-in implementation. We just need to re-baseline the test.
Created attachment 236220 [details] the patch
Landed in r172264: <http://trac.webkit.org/r172264>.