Some canvas tests only fail on Mac EWS
https://bugs.webkit.org/show_bug.cgi?id=112176

Reviewed by Simon Fraser.

Add Failure / Pass test expectations on tests that only fail on Mac EWS bots.

Ideally, we can figure out the root cause of this failure and fix that problem but we haven't been able
to do so. We also don't have a way of adding test expectations only on EWS bots we're out of luck here.

* platform/mac/TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145577 268f45cc-cd09-0410-ab3c-d52691b4dbfc