Break config_default into master_site_configs.

masters/master.client.dart/master.cfg

 # -*- python -*-
 # ex: set syntax=python:
 
 # 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.
 
 # It has one job: define a dictionary named BuildmasterConfig. This
 # dictionary has a variety of keys to control different aspects of the
 # buildmaster. They are documented in docs/config.xhtml .
 
 from buildbot import locks
 from buildbot.scheduler import Dependent
 from buildbot.scheduler import Scheduler
 from buildbot.scheduler import Periodic
 
 from common import chromium_utils
 from master import build_utils
 from master import chromium_step
 from master import master_utils
 from master import slaves_list
 from master.factory import gclient_factory
 from master.factory import dart_factory
 from master.factory.dart_factory import linux_env, windows_env, linux_clang_env
 
 import config
-ActiveMaster = config.Master.Dart
+import master_site_config
+ActiveMaster = master_site_config.Dart
 utils = dart_factory.DartUtils(ActiveMaster)
 
 # Hack to increase timeout for steps, dart2js debug checked mode takes more
 # than 8 hours.
 utils.monkey_patch_remoteshell()
 
 MASTER_HOST = ActiveMaster.master_host
 WEB_STATUS = True
 MAIL_NOTIFIER = ActiveMaster.is_production_host
 GOOD_REVISIONS = ActiveMaster.is_production_host
@@ skipping 765 matching lines @@
 c['projectName'] = ActiveMaster.project_name
 c['projectURL'] = config.Master.project_url
 
 # the 'buildbotURL' string should point to the location where the buildbot's
 # internal web server (usually the html.Waterfall page) is visible. This
 # typically uses the port number set in the Waterfall 'status' entry, but
 # with an externally-visible host name which the buildbot cannot figure out
 # without some help.
 
 c['buildbotURL'] = 'http://build.chromium.org/p/client.dart/'