Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/adb/api.py

 # Copyright (c) 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 AdbApi(recipe_api.RecipeApi):
   def __init__(self, **kwargs):
     super(AdbApi, self).__init__(**kwargs)
     self._custom_adb_path = None
     self._devices = None
 
   def __call__(self, cmd, serial=None, **kwargs):
     """Run an ADB command."""
     cmd_prefix = [self.adb_path()]
@@ skipping 38 matching lines @@
         """
         import subprocess
         import sys
         adb_path = sys.argv[1]
         for device in sys.argv[2:]:
           subprocess.check_call([adb_path, '-s', device, 'root'])
           subprocess.check_call([adb_path, '-s', device, 'wait-for-device'])
         """,
         args=[self.adb_path()] + self.devices,
         **kwargs)