Gerrit testing framework.

cros_test_lib.GerritTestCase is responsible for creating a gerrit
instance running on localhost, and patching up buildbot/constants.py
to point to the local gerrit instance.

lib.gerrit_unittests.GerritHelperTest.test001_simple_query is the
first test to use the new framework.

BUG=280620
TEST=None

Change-Id: Ic098f3630ae4a6bca49ca1f88d48c2220a81783c
Reviewed-on: https://chromium-review.googlesource.com/168671
Reviewed-by: Stefan Zager <szager@chromium.org>
Commit-Queue: Stefan Zager <szager@chromium.org>
Tested-by: Stefan Zager <szager@chromium.org>
diff --git a/scripts/cros_sdk.py b/scripts/cros_sdk.py
index 434c3b0..09c41c8 100644
--- a/scripts/cros_sdk.py
+++ b/scripts/cros_sdk.py
@@ -196,9 +196,7 @@
 
   # Pass in the path to the depot_tools so that users can access them from
   # within the chroot.
-  gclient = osutils.Which('gclient')
-  if gclient is not None:
-    cmd += ['DEPOT_TOOLS=%s' % os.path.realpath(os.path.dirname(gclient))]
+  cmd += ['DEPOT_TOOLS=%s' % cros_build_lib.FindDepotTools()]
 
   return cmd