Move recipe engine to third_party/recipe_engine.

scripts/slave/recipe_modules/webrtc/chromium_config.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.recipe_config import BadConf
+from recipe_engine.config import BadConf
+from recipe_engine.config_types import Path
 
 import DEPS
 CONFIG_CTX = DEPS['chromium'].CONFIG_CTX
-from slave.recipe_config_types import Path
 
 
 SUPPORTED_TARGET_ARCHS = ('intel', 'arm')
 
 
 @CONFIG_CTX(includes=['chromium', 'dcheck'])
 def webrtc_standalone(c):
   _compiler_defaults(c)
 
   c.runtests.memory_tests_runner = Path('[CHECKOUT]', 'tools',
@@ skipping 28 matching lines @@
 
 @CONFIG_CTX(includes=['gn'])
 def webrtc_gn(c):
   c.compile_py.default_targets = ['all']
   c.project_generator.args = ['build_with_chromium=false']
 
 def _compiler_defaults(c):
   c.compile_py.default_targets = ['All']
   if c.TARGET_PLATFORM in ('mac', 'ios'):
     c.gyp_env.GYP_DEFINES['mac_sdk'] = '10.9'