Break config_default into master_site_configs.

scripts/master/factory/gclient_factory.py

 # Copyright (c) 2012 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.
 
 """Utility classes to generate and manage a BuildFactory to be passed to a
 builder dictionary as the 'factory' member, for each builder in c['builders'].
 
 Specifically creates a base BuildFactory that will execute a gclient checkout
 first."""
 
@@ skipping 307 matching lines @@
         no_gclient_branch=no_gclient_branch,
         no_gclient_revision=no_gclient_revision,
         gclient_transitive=gclient_transitive,
         primary_repo=primary_repo,
         gclient_jobs=gclient_jobs,
         blink_config=blink_config)
 
     if slave_type in ('AnnotatedTrybot', 'CrosTrybot', 'Trybot', 'Bisect'):
       factory_cmd_obj.AddApplyIssueStep(
           timeout=timeout,
-          server=config.Master.TryServer.code_review_site)
+          server=config.Master.Master4.code_review_site)
 
     if not self._nohooks_on_update:
       factory_cmd_obj.AddRunHooksStep(env=env, timeout=timeout)