Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/isolate/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_api
+from recipe_engine import recipe_api
 
 
 class IsolateApi(recipe_api.RecipeApi):
   """APIs for interacting with isolates."""
 
   def __init__(self, **kwargs):
     super(IsolateApi, self).__init__(**kwargs)
     self._isolate_server = 'https://isolateserver.appspot.com'
     self._isolated_tests = {}
 
@@ skipping 265 matching lines @@
     """Compare the artifacts from 2 builds."""
     args = [
         '--first-build-dir', first_dir,
         '--second-build-dir', second_dir,
         '--target-platform', self.m.chromium.c.TARGET_PLATFORM
     ]
     self.m.python('compare_build_artifacts',
                   self.resource('compare_build_artifacts.py'),
                   args=args,
                   cwd=self.m.path['slave_build'])