api.trigger: refactoring, made extensible

scripts/slave/recipe_modules/step/config.py

 # Copyright 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.
 
 import collections
 
 from slave.recipe_config import List
 from slave.recipe_config import (config_item_context, ConfigGroup, ConfigList,
                                  Dict, Single, Set)
 from slave.recipe_config_types import Path
@@ skipping 17 matching lines @@
     cwd = Single(Path, jsonish_fn=str, required=False),
 
     stdout = Single(Placeholder, required=False),
     stderr = Single(Placeholder, required=False),
     stdin = Single(Placeholder, required=False),
 
     allow_subannotations = Single(bool, required=False),
 
     trigger_specs = ConfigList(
         lambda: ConfigGroup(
+            builder_name=Single(basestring),
             properties=Dict(value_type=object),
+            buildbot_changes=List(dict),
         ),
     ),
 
     step_test_data = Single(collections.Callable, required=False),
 
     ok_ret = Set(int),
     infra_step = Single(bool, required=False)
   )
 
 
 config_ctx = config_item_context(BaseConfig, {'_DUMMY': ['val']}, 'example')
 
 @config_ctx()
 def test(c):  # pragma: no cover
   c.name = 'test'
   c.cmd = [Path('[CHECKOUT]', 'build', 'tools', 'cool_script.py')]