Don't require a .dbconfig file on any masters.

masters/master.chromiumos/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.
 
 # This is the buildmaster config file for the 'chromeos' bot. It must
 # be installed as 'master.cfg' in your buildmaster's base directory
 # (although the filename can be changed with the --basedir option to
@@ skipping 28 matching lines @@
 from master.cros import builder_config
 from common.cros_chromite import ChromiteTarget
 
 ActiveMaster = master_site_config.ChromiumOS
 DRY_RUN = not ActiveMaster.is_production_host
 
 # This is the dictionary that the buildmaster pays attention to. We also use
 # a shorter alias to save typing.
 c = BuildmasterConfig = {}
 
-config.DatabaseSetup(c, require_dbconfig=ActiveMaster.is_production_host)
+config.DatabaseSetup(c)
 
 
 # ----------------------------------------------------------------------------
 # BUILDER DEFINITIONS
 
 # Annotator factory object.
 factory_obj = annotator_factory.AnnotatorFactory(
     active_master=ActiveMaster)
 
 # The 'builders' list defines the Builders. Each one is configured with a
@@ skipping 219 matching lines @@
   # gets generated.
   chromiumos_board_config.slave_allocator.SaveState()
   slave_map = chromiumos_board_config.slave_allocator.GetSlaveMap()
   if slave_map.unallocated:
     log.msg("The following slaves were not allocated: %s" % (
         sorted(slave_map.unallocated),))
 
   # Disable 'auto_reboot' on slaves for local testing.
   for builder in c['builders']:
     builder['auto_reboot'] = False