Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/isolate/test_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.
 
-from slave import recipe_test_api
+from recipe_engine import recipe_test_api
 
 class IsolateTestApi(recipe_test_api.RecipeTestApi):
   def output_json(self, targets=None, missing=None):
     """Mocked output of 'find_isolated_tests' and 'isolate_tests' steps.
 
     Deterministically synthesizes json.output test data for the given targets.
     If |targets| is None, will emit test data with some dummy targets instead,
     emulating find_isolated_tests.py finding some files.
 
     If |missing| is given it's a subset of |targets| that wasn't isolated in
     'isolate_tests' due to some error.
     """
     missing = missing or ()
     if targets is None:
       targets = ['dummy_target_1', 'dummy_target_2']
     return self.m.json.output({
       target: None if target in missing else '[dummy hash for %s]' % target
       for target in targets
     })