LayoutTests: Disable Mac tests failing on 10.9 with no GPU.

See https://luci-milo.appspot.com/buildbot/chromium.fyi/WebKit%20Mac%20-%20RandomOrder/6820

BUG=736177
TBR=kbr@chromium.org,qyearsley@chromium.org,jeffcarp@chromium.org,ericrk@chromium.org,enne@chromium.org,dpranke@chromium.org,ccameron@chromium.org
NOTRY=true

Change-Id: Ie70b7fc17d617e57c3fe9638a3c2ff406714fd8e
Reviewed-on: https://chromium-review.googlesource.com/611778
Commit-Queue: Tim 'mithro' Ansell <tansell@chromium.org>
Reviewed-by: Tim 'mithro' Ansell <tansell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#493996}
1 file changed