Add simple depends_on API.

recipe_engine/loader.py

 # Copyright 2013-2015 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.
 
 import collections
 import contextlib
 import imp
 import inspect
 import os
 import sys
@@ skipping 113 matching lines @@
   # TODO(luqui): Forbid depending on a module from a (locally) undeclared
   # dependency.
   def __init__(self, package, module, local_name, universe):
     mod_path = (
         universe.package_deps.get_package(package).module_path(module))
     super(PackageDependency, self).__init__(
         mod_path, local_name, universe=universe)
 
 
 class RecipeUniverse(object):
-  def __init__(self, package_deps):
+  def __init__(self, package_deps, config_file):
     self._loaded = {}
     self._package_deps = package_deps
+    self._config_file = config_file
 
   @property
   def module_dirs(self):
     return self._package_deps.all_module_dirs
 
   @property
   def recipe_dirs(self):
     return self._package_deps.all_recipe_dirs
 
   @property
@@ skipping 349 matching lines @@
     return modapi
 
   mapper = DependencyMapper(instantiator)
   api = RecipeTestApi(module=None)
   for k,v in toplevel_deps.iteritems():
     setattr(api, k, mapper.instantiate(v))
   return api