Break config_default into master_site_configs.

masters/master.chromium.swarm/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.
 
 from buildbot.changes import svnpoller
 from buildbot.scheduler import Scheduler
 
 from master import build_utils
 from master import gatekeeper
 from master import chromium_step
 from master import master_utils
 from master import slaves_list
 from master.factory import swarm_factory
 
 import config
+import master_site_config
 
-ActiveMaster = config.Master.ChromiumSwarm
+ActiveMaster = master_site_config.ChromiumSwarm
 
 # This is the dictionary that the buildmaster pays attention to. We also use
 # a shorter alias to save typing.
 c = BuildmasterConfig = {}
 
 # 'slavePortnum' defines the TCP port to listen on. This must match the value
 # configured into the buildslaves (with their --master option)
 c['slavePortnum'] = ActiveMaster.slave_port
 
 config.DatabaseSetup(c, require_dbconfig=ActiveMaster.is_production_host)
@@ skipping 274 matching lines @@
         subject='chromium.swarm %(result)s in %(projectName)s '
                 'on %(builder)s',
         extraRecipients=['csharp@chromium.org', 'maruel@chromium.org'],
         sendToInterestedUsers=False))
 
 ####### PROJECT IDENTITY
 
 c['projectName'] = ActiveMaster.project_name
 c['projectURL'] = config.Master.project_url
 c['buildbotURL'] = 'http://build.chromium.org/p/chromium.swarm/'