Add *_ng bots to tryserver.chromium.linux (synchronized with main waterfall)

masters/master.tryserver.chromium.linux/slaves.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.
 
 # See master.experimental/slaves.cfg for documentation.
 
 
 def expand_extra_builders(extras, total):
@@ skipping 27 matching lines @@
   linux_arm_testers = [9]
 
   # Have a dedicated pool for presubmit jobs - all CQ jobs
   # need a presubmit first and so must be responsive.
   presubmit_builders = ['chromium_presubmit', 'blink_presubmit']
 
   # Configurations on every VM.
   base = presubmit_builders + [
     # One line per shared directory. In decreasing usage:
     'linux_chromium_dbg', 'linux_chromium_rel', 'linux_chromium_rel_swarming',
+    'linux_chromium_dbg_ng', 'linux_chromium_rel_ng',
     'linux_chromium_compile_dbg', 'linux_chromium_compile_rel',
     'linux_rel_naclmore',
     'linux_chromium_gn_dbg', 'linux_chromium_gn_rel',
     'android_chromium_gn_compile_dbg',
     'android_chromium_gn_compile_dbg_recipe',
     'android_chromium_gn_compile_rel',
     'android_chromium_gn_compile_rel_recipe',
 
     'linux_chromium_clang_dbg', 'linux_chromium_clang_rel',
 
@@ skipping 216 matching lines @@
       'os': 'linux',
       'version': 'precise',
       'bits': '64',
     } for i in range(520, 550)
   ]
 
   return compile_slaves + test_slaves + aosp_slaves
 
 
 slaves = linux() + android()