GitLab

This CL lets us prepare to remove BuildSlaveSupport. This patch is step 07 of
pyclean but was created manually.

Review URL: https://codereview.chromium.org/13712005

git-svn-id: svn://svn.chromium.org/blink/trunk@147586 bbb929c8-8fbe-4397-9dbb-9b2b20218538