Checking in a small tool that has customizable hooks to recover DUTs.

Checking in a new tool that runs after failsafe.conf has started
(30s in to boot or after Chrome has booted) that will run a set of hooks
on Chromium/Chrome OS test images that check "bricked" conditions and fix them.
I'm starting with a hook that toggles eth0 and restarts shill if we can't reach
www.google.com.

BUG=chromium-os:34178
TEST=Ran it and checked logs

Change-Id: I65f1c0eec61ff4dac04478d8bf2e94abd0609dbe
Reviewed-on: https://gerrit.chromium.org/gerrit/32453
Commit-Ready: Chris Sosa <sosa@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
3 files changed