Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/test_utils/api.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.
 
-from slave import recipe_api
-from slave import recipe_util
+from recipe_engine import recipe_api
+from recipe_engine import util as recipe_util
 
 from .util import GTestResults, TestResults
 
 # TODO(luqui): Destroy this DEPS hack.
 import DEPS
 JsonOutputPlaceholder = DEPS['json'].api.JsonOutputPlaceholder
 
 class TestResultsOutputPlaceholder(JsonOutputPlaceholder):
   def result(self, presentation, test):
     ret = super(TestResultsOutputPlaceholder, self).result(presentation, test)
@@ skipping 180 matching lines @@
     """A placeholder which will expand to
     '--test-launcher-summary-output=/tmp/file'.
 
     Provides the --test-launcher-summary-output flag since --flag=value
     (i.e. a single token in the command line) is the required format.
 
     The test_results will be an instance of the GTestResults class.
     """
     return GTestResultsOutputPlaceholder(self, add_json_log)