Add "root" variable to DEPS. This variable can be used to override the root location of the .git for ANGLE relative to gclient, so our DEPS can work with both ANGLE standalone and the new bot configurations that are being added by thakis@. Bug: chromium:820421 Change-Id: I5cd57bc88fcd4dc69e82aa1e59d343f1eaf6f5ee Reviewed-on: https://chromium-review.googlesource.com/1012506 Commit-Queue: Nico Weber <thakis@chromium.org> Reviewed-by: Nico Weber <thakis@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>