Break config_default into master_site_configs.

masters/master.chromium/master.cfg

 # 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.
 
 # These modules come from scripts/master, which must be in the PYTHONPATH.
 from master import master_utils
 from master import slaves_list
 
 import config
+import master_site_config
 
-ActiveMaster = config.Master.Chromium
+ActiveMaster = master_site_config.Chromium
 
 # Only the production Chromium Buildbot acts as the tree gatekeeper.
 TREE_GATE_KEEPER = ActiveMaster.is_production_host
 
 c = BuildmasterConfig = {}
 c['change_source'] = []
 c['schedulers'] = []
 c['builders'] = []
 c['status'] = []
 
@@ skipping 31 matching lines @@
 # Adds common status and tools to this master.
 master_utils.AutoSetupMaster(c, ActiveMaster,
     enable_http_status_push=ActiveMaster.is_production_host)
 
 # Do it at the end to override values set by AutoSetupMaster, the default is
 # too low. Must keep at least a few days worth of builds.
 c['buildHorizon'] = 3000
 c['logHorizon'] = 3000
 # Must be at least 2x the number of slaves.
 c['eventHorizon'] = 200