Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/trigger/api.py

 # Copyright 2014 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.
 
 """This recipe module allows triggering builds within the same master.
 
 See README.md.
 """
 
-from slave import recipe_api
+from recipe_engine import recipe_api
 
 
 class TriggerApi(recipe_api.RecipeApi):
   """APIs for triggering new builds."""
 
   def __init__(self, **kwargs):
     super(TriggerApi, self).__init__(**kwargs)
 
   def _port_from_properties_only(self, trigger_spec):
     """Convert from previous "properties-only" mode to trigger spec."""
@@ skipping 82 matching lines @@
       builder_names.add(builder_name)
 
     result = self.m.step(
         kwargs.get('name', 'trigger'),
         cmd=[],
         trigger_specs=trigger_specs,
     )
     if 'name' not in kwargs:
       result.presentation.step_text = "<br />".join(sorted(builder_names))
     return result