Add a new buildbot-tool generator for master configs

scripts/tools/buildbot_tool_templates/buildbot.tac

Index: scripts/tools/buildbot_tool_templates/buildbot.tac
diff --git a/scripts/tools/buildbot_tool_templates/buildbot.tac b/scripts/tools/buildbot_tool_templates/buildbot.tac
new file mode 100644
index 0000000000000000000000000000000000000000..1a998ac4ff0bd9ebdab6442bcbd6f1f93f60a00d
--- /dev/null
+++ b/scripts/tools/buildbot_tool_templates/buildbot.tac
@@ -0,0 +1,16 @@
+# 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.
+
+# This file is used by scripts/tools/buildbot-tool to generate master configs.
+
+import os
+
+from twisted.application import service
+from buildbot.master import BuildMaster
+
+basedir = os.path.dirname(os.path.abspath(__file__))
+configfile = 'master.cfg'
+
+application = service.Application('buildmaster')
+BuildMaster(basedir, configfile).setServiceParent(application)