removing legacy optiplex "grandma-pc" slaves
removing legacy optiplex "grandma-pc" slaves

R=phajdan.jr@chromium.org, stip@chromium.org
BUG=

Review URL: https://codereview.chromium.org/198053010

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@257574 0039d316-1c4b-4281-b951-d872f2087c98

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