expect_tests and testing_support are now pulled in via DEPS.

R=cmp@chromium.org, pgervais@chromium.org
BUG=

Review URL: https://codereview.chromium.org/901083003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@293963 0039d316-1c4b-4281-b951-d872f2087c98