Remove XP and Vista bots from chromium.win and chromium.webkit waterfalls.

BUG=579196

Review URL: https://codereview.chromium.org/1608713004

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/build@298385 0039d316-1c4b-4281-b951-d872f2087c98
22 files changed