Skipping css3/flexbox/flexitem.html.
https://bugs.webkit.org/show_bug.cgi?id=94723.

Patch by Mark Lam <mark.lam@apple.com> on 2012-08-22
Reviewed by Simon Fraser.

* platform/mac/Skipped:

git-svn-id: svn://svn.chromium.org/blink/trunk@126337 bbb929c8-8fbe-4397-9dbb-9b2b20218538