Add simple depends_on API.

recipe_engine/run.py

 # Copyright (c) 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.
 
 """Entry point for fully-annotated builds.
 
 This script is part of the effort to move all builds to annotator-based
 systems. Any builder configured to use the AnnotatorFactory.BaseFactory()
 found in scripts/master/factory/annotator_factory.py executes a single
 AddAnnotatedScript step. That step (found in annotator_commands.py) calls
@@ skipping 415 matching lines @@
   properties.pop('root', None)
 
   # TODO(iannucci): A much better way to do this would be to dynamically
   #   detect if the mirrors are actually available during the execution of the
   #   recipe.
   if ('use_mirror' not in properties and (
     'TESTING_MASTERNAME' in os.environ or
     'TESTING_SLAVENAME' in os.environ)):
     properties['use_mirror'] = False
 
-  engine = RecipeEngine(stream, properties, test_data)
+  engine = RecipeEngine(stream, properties, test_data, universe)
 
   # Create all API modules and top level RunSteps function.  It doesn't launch
   # any recipe code yet; RunSteps needs to be called.
   api = None
   with stream.step('setup_build') as s:
     assert 'recipe' in properties
     recipe = properties['recipe']
 
     properties_to_print = properties.copy()
     if 'use_mirror' in properties:
@@ skipping 296 matching lines @@
   Knows how to execute steps emitted by a recipe, holds global state such as
   step history and build properties. Each recipe module API has a reference to
   this object.
 
   Recipe modules that are aware of the engine:
     * properties - uses engine.properties.
     * step_history - uses engine.step_history.
     * step - uses engine.create_step(...).
 
   """
-  def __init__(self, stream, properties, test_data):
+  def __init__(self, stream, properties, test_data, universe):
     self._stream = stream
     self._properties = properties
     self._test_data = test_data
     self._step_history = collections.OrderedDict()
+    self._universe = universe
 
     self._previous_step_annotation = None
     self._previous_step_result = None
     self._api = None
 
   @property
   def properties(self):
     return self._properties
 
   @property
@@ skipping 86 matching lines @@
         exc = recipe_api.InfraFailure
 
       step_result.presentation.status = state
       if step_test.enabled:
         # To avoid cluttering the expectations, don't emit this in testmode.
         self._previous_step_annotation.emit(
             'step returned non-zero exit code: %d' % step_result.retcode)
 
       raise exc(step['name'], step_result)
 
-
   def run(self, recipe_script, api):
     """Run a recipe represented by a recipe_script object.
 
     This function blocks until recipe finishes.
 
     Args:
       recipe_script: The recipe to run, as represented by a RecipeScript object.
       api: The api, with loaded module dependencies.
            Used by the some special modules.
 
@@ skipping 59 matching lines @@
     Args:
       step: ConfigGroup object with information about the step, see
         recipe_modules/step/config.py.
 
     Returns:
       Opaque engine specific object that is understood by 'run_steps' method.
     """
     return step.as_jsonish()