Land failing baselines for Lion after r141333. Unreviewed.
https://bugs.webkit.org/show_bug.cgi?id=108523

* platform/mac-lion/fast/canvas/canvas-composite-alpha-expected.txt: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141506 268f45cc-cd09-0410-ab3c-d52691b4dbfc