Update Mac WebKit2 test expectations for flaky and failing tests.

* platform/mac-wk2/TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148361 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Python test fix attempt after r148360.

* Scripts/webkitpy/tool/multicommandtool_unittest.py:
(test_command_help):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148362 268f45cc-cd09-0410-ab3c-d52691b4dbfc