Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/gatekeeper/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.
 
 import json
 
-from slave import recipe_test_api
+from recipe_engine import recipe_test_api
 
 
 class GatekeeperTestApi(recipe_test_api.RecipeTestApi):
   def fake_test_data(self):
     return self.m.json.output({
       'blink': {
         'build-db': 'blink_build_db.json',
         'masters': [
           'https://build.chromium.org/p/chromium.webkit',
         ],
         'filter-domain': 'google.com',
         'open-tree': True,
         'password-file': '.blink_status_password',
         'revision-properties': 'got_revision,got_webkit_revision',
         'set-status': True,
         'sheriff-url': 'https://build.chromium.org/p/chromium/%s.js',
         'status-url': 'https://blink-status.appspot.com',
         'status-user': 'gatekeeper@google.com',
         'track-revisions': True,
         'use-project-email-address': True,
       },
       'chromium': {},
     })
 
   def read_real_config(self, f):
     return self.m.json.output(json.loads(self.m.file.read_in_build(f)))
 
   def read_real_internal_config(self, f): # pragma nocover
     return self.m.json.output(json.loads(self.m.file.read_in_build_internal(f)))