Move recipe engine to third_party/recipe_engine.

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
-from slave.recipe_util import Placeholder
+from recipe_engine.config import List
+from recipe_engine.config import (config_item_context, ConfigGroup, ConfigList,
+                          Dict, Single, Set)
+from recipe_engine.config_types import Path
+from recipe_engine.util import Placeholder
 
 
 def BaseConfig(**_kwargs):
   def render_cmd(lst):
     return [(x if isinstance(x, Placeholder) else str(x)) for x in lst]
 
   return ConfigGroup(
     # For compatibility with buildbot, the step name must be ascii, which is why
     # this is a 'str' and not a 'basestring'.
     name = Single(str),
@@ skipping 26 matching lines @@
     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')]