Turn off antialiases text on the Mac during the layout tests.

Using antialiased text causes thousands of pixel test differences
between different versions of the operating system, and causes
hundreds of reference test failures. This patch turns it off :).

Also, this patch temporarily adds a mac-specific MacExpectations file
to skip all of the tests that will require new baselines. This keeps
the layout test archives on the bots small, and keeps the bots from
retrying thousands of failures, until all of the new baselines have
been uploaded. I will remove the MacExpectations file at that point.

R=ojan@chromium.org
BUG=264088

git-svn-id: svn://svn.chromium.org/blink/trunk@155476 bbb929c8-8fbe-4397-9dbb-9b2b20218538