fast/regions/layers/region-removed-during-animation.html is flaky
https://bugs.webkit.org/show_bug.cgi?id=139979

* platform/mac-wk2/TestExpectations: Marking as such.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@177785 268f45cc-cd09-0410-ab3c-d52691b4dbfc