This reverts commit 5705acab.

Reason for revert: breaks internal bots, e.g. see http://shortn/_KDb4blyDVz

Original change's description:
> [gclient] Make getdep and setdep to provide builtin vars
> 
> Bug: 906114
> Change-Id: I069cc21343911f7fdb3c91ecbd8fcba53fc8099f
> Reviewed-on: https://chromium-review.googlesource.com/c/1340461
> Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
> Commit-Queue: Eric Boren <borenet@chromium.org>

TBR=borenet@chromium.org,ehmaldonado@chromium.org

Change-Id: I233ae7feae296fb4cd04b9b36d7f53d1114df5ff
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 906114
Reviewed-on: https://chromium-review.googlesource.com/c/1340506Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>