Add simple depends_on API.

recipes.py

 #!/usr/bin/env python
 
 """Tool to interact with recipe repositories.
 
 This tool operates on the nearest ancestor directory containing an
 infra/config/recipes.cfg.
 """
 
 import argparse
 import json
@@ skipping 13 matching lines @@
   assert os.path.exists(args.package), (
       'Given recipes config file %s does not exist.' % args.package)
   return (
       package.InfraRepoConfig().from_recipes_cfg(args.package),
       package.ProtoFile(args.package)
   )
 
 
 def simulation_test(package_deps, args):
   from recipe_engine import simulation_test
-  simulation_test.main(package_deps, args=json.loads(args.args))
+  from recipe_engine import loader
+
+  _, config_file = get_package_config(args)
+  universe = loader.RecipeUniverse(package_deps, config_file.path)
+
+  simulation_test.main(universe, args=json.loads(args.args))
 
 
 def lint(package_deps, args):
   from recipe_engine import lint_test
   lint_test.main(package_deps, args.whitelist or [])
 
 
 def handle_recipe_return(recipe_result, result_filename, stream):
     if 'recipe_result' in recipe_result.result:
       result_string = json.dumps(
@@ skipping 49 matching lines @@
   elif args.properties_file:
     properties = get_properties_from_file(args.properties_file)
   else:
     properties = arg_properties
 
   properties['recipe'] = args.recipe
 
   os.environ['PYTHONUNBUFFERED'] = '1'
   os.environ['PYTHONIOENCODING'] = 'UTF-8'
 
-  universe = loader.RecipeUniverse(package_deps)
+  _, config_file = get_package_config(args)
+  universe = loader.RecipeUniverse(package_deps, config_file.path)
 
   workdir = (args.workdir or
       os.path.join(os.path.dirname(os.path.realpath(__file__)), 'workdir'))
   logging.info('Using %s as work directory' % workdir)
   if not os.path.exists(workdir):
     os.makedirs(workdir)
 
   old_cwd = os.getcwd()
   os.chdir(workdir)
   stream = annotator.StructuredAnnotationStream()
 
   try:
     ret = recipe_run.run_steps(properties, stream, universe=universe)
-
   finally:
     os.chdir(old_cwd)
 
   return handle_recipe_return(ret, args.result_file, stream)
 
 
 def roll(args):
   from recipe_engine import package
   repo_root, config_file = get_package_config(args)
   context = package.PackageContext.from_proto_file(repo_root, config_file)
@@ skipping 201 matching lines @@
 
     Warmly,
     recipes.py
     """
     return 1
 
   return 0
 
 if __name__ == '__main__':
   sys.exit(main())