Update buildbot_tool and builders.pyl templates to remove 'master_type'.

scripts/master/master_gen.py

 # Copyright 2014 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.
 
 import ast
 import os
 
 from buildbot.schedulers.basic import SingleBranchScheduler
 from buildbot.status.mail import MailNotifier
 
@@ skipping 23 matching lines @@
   c['projectURL'] = Master.project_url
   c['buildbotURL'] = active_master_cls.buildbot_url
 
   # This sets c['db_url'] to the database connect string in found in
   # the .dbconfig in the master directory, if it exists. If this is
   # a production host, it must exist.
   chromium_utils.DatabaseSetup(
       c,
       require_dbconfig=active_master_cls.is_production_host)
 
-  if builders['master_type'] == 'waterfall':
+  # TODO(dpranke): crbug.com/492876. Rework this when we add support for
+  # multiple schedulers.
+  if 'git_repo_url' in builders:
     change_source = gitiles_poller.GitilesPoller(builders['git_repo_url'])
     c['change_source'] = [change_source]
     tag_comparator = change_source.comparator
   else:
-    assert builders['master_type'] == 'tryserver'
     c['change_source'] = []
     c['mergeRequests'] = False
     tag_comparator = None
 
   c['builders'] = []
   for builder_name, builder_data in builders['builders'].items():
     c['builders'].append({
         'auto_reboot': builder_data.get('auto_reboot', True),
         'name': builder_name,
         'factory': m_annotator.BaseFactory(),
@@ skipping 30 matching lines @@
       templates=builders['templates'],
       tagComparator=tag_comparator,
       enable_http_status_push=active_master_cls.is_production_host)
 
   # TODO: AutoSetupMaster's settings for the following are too low to be
   # useful for most projets. We should fix that.
   c['buildHorizon'] = 3000
   c['logHorizon'] = 3000
   # Must be at least 2x the number of slaves.
   c['eventHorizon'] = 200