Revert of Cross-repo recipe package system.

scripts/slave/recipes/gatekeeper.py

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Launches the gatekeeper."""
 
 
 DEPS = [
   'gatekeeper',
   'path',
 ]
 
 
 def RunSteps(api):
   api.gatekeeper(
     api.path['build'].join('scripts', 'slave', 'gatekeeper.json'),
     api.path['build'].join('scripts', 'slave', 'gatekeeper_trees.json'),
   )
 
 
 def GenTests(api):
+  # It is okay to use os here because we are reading the file immediately
+  # on the simulating machine.
+  import os
+
   yield (
     api.test('basic')
     + api.step_data(
       'reading gatekeeper_trees.json',
       api.gatekeeper.fake_test_data(),
     )
   )
 
+  yield (
+    api.test('real')
+    + api.step_data(
+      'reading gatekeeper_trees.json',
+      api.gatekeeper.read_real_config(
+        os.path.join('scripts', 'slave', 'gatekeeper_trees.json')
+      ),
+    )
+  )
+
   yield (
     api.test('keep_going')
     + api.step_data(
       'reading gatekeeper_trees.json',
       api.gatekeeper.fake_test_data(),
     )
     + api.step_data('gatekeeper: chromium', retcode=1)
   )