Some changes to allow recipes and modules to live noncentrally

scripts/slave/recipes/chromium_gn.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 infra.libs.infra_types import freeze
 
 DEPS = [
   'bot_update',
   'chromium',
   'chromium_tests',
   'json',
   'path',
   'platform',
   'properties',
   'step',
   'test_utils',
   'tryserver',
+  'webrtc',
 ]
 
 
 BUILDERS = freeze({
   'chromium.mac': {
     'builders': {
       'Mac GN': {
         'chromium_config_kwargs': {
           'BUILD_CONFIG': 'Release',
           'TARGET_PLATFORM': 'mac',
@@ skipping 544 matching lines @@
            'gtest_tests': ['base_unittests'],
         }})) +
     api.override_step_data(
         'analyze',
         api.json.output({
           'status': 'Found dependency',
           'targets': ['net_unittests'],
           'build_targets': ['net_unittests'],
         }))
   )