Add 2 Mac baremetal slaves
Add 2 Mac baremetal slaves

BUG=431479

Review URL: https://codereview.chromium.org/1214223003

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@295878 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build