Unreviewed cleanup. Remove media/track/ from Mac TestExpectations because 
https://bugs.webkit.org/show_bug.cgi?id=105606 was fixed.

* platform/mac/TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@138867 268f45cc-cd09-0410-ab3c-d52691b4dbfc