Add a config for optional UBSan trybot.

masters/master.tryserver.chromium.linux/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.
 
 # READ THIS:
 # See http://dev.chromium.org/developers/testing/chromium-build-infrastructure
 
 import os
@@ skipping 146 matching lines @@
     'factory': m_remote_run_chromium_src('chromium_trybot'),
     'slavebuilddir': 'remote_run',
 })
 
 chromium_builders.append({
     'name': 'linux_chromium_cfi_rel_ng',
     'factory': m_remote_run_chromium_src('chromium_trybot', timeout=12000),
     'slavebuilddir': 'remote_run',
 })
 
+chromium_builders.append({
+    'name': 'linux_chromium_ubsan_rel_ng',
+    'factory': m_remote_run_chromium_src(
+        'chromium_trybot', max_time=master_utils.CQ_MAX_TIME),
+    'slavebuilddir': 'remote_run',
+})
+
 chromium_builders.extend([{
     'name': 'linux_arm',
     'factory': m_remote_run_chromium_src('chromium_trybot'),
     'slavebuilddir': 'remote_run',
   },
 ])
 
 chromium_builders.append({
   'name': 'linux_chromium_compile_dbg_32_ng',
   'factory': m_remote_run_chromium_src(
@@ skipping 381 matching lines @@
 #  base.make_stop_form = hack_stop(base.make_stop_form)
 
 
 ####### PROJECT IDENTITY
 
 # The 'projectURL' string will be used to provide a link
 # from buildbot HTML pages to your project's home page.
 c['projectURL'] = 'http://dev.chromium.org/developers/testing/try-server-usage'
 
 # vi: set ts=4 sts=2 sw=2 et: