Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/platform/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.
 
 import sys
 import platform
 
-from slave import recipe_api
+from recipe_engine import recipe_api
 
 
 def norm_plat(plat):
   if plat.startswith('linux'):
     return 'linux'
   elif plat.startswith(('win', 'cygwin')):
     return 'win'
   elif plat.startswith(('darwin', 'mac')):
     return 'mac'
   else:  # pragma: no cover
@@ skipping 64 matching lines @@
     return self._bits
 
   @property
   def arch(self):
     return self._arch
 
   @staticmethod
   def normalize_platform_name(platform):
     """One of python's sys.platform values -> 'win', 'linux' or 'mac'."""
     return norm_plat(platform)  # pragma: no cover