Add mb configuration for headless trybot

tools/mb/mb_config.pyl

 # Copyright 2015 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 a map of buildbot master names -> buildbot builder names ->
   # config names (where each config name is a key in the 'configs' dict,
   # below). MB uses this dict to look up which config to use for a given bot.
   'masters': {
     'chromeos.chrome': {
@@ skipping 881 matching lines @@
       'linux_chromium_webkit_msan_variable': 'findit',
       'linux_chromium_webkit_variable': 'findit',
       'linux_chromiumos_full_variable': 'findit',
 
       # This is 'release_bot' rather than 'release_trybot' because
       # 'release_trybot' includes 'dcheck_always_on', which might cause
       # some layout test results to be different than for normal release
       # builds (and we only store baselines for release builds).
       'linux_layout_tests_slimming_paint_v2': 'swarming_gn_release_bot',
 
+      'linux_chromium_headless_dbg':
+        ('//build/args/bots/tryserver.chromium.linux/'
+         'headless_linux_dbg_trybot.gn'),
+
       'linux_nacl_sdk_build': 'gn_release_bot',
       'linux_nacl_sdk': 'gn_release_bot',
       'linux_optional_gpu_tests_rel':
         'swarming_gpu_fyi_tests_gn_release_trybot',
       'linux_site_isolation': 'gn_release_trybot',
       'linux_upload_clang': 'gn_release_bot',
     },
 
     'tryserver.chromium.mac': {
       'ios-device': 'ios_gn',
@@ skipping 1579 matching lines @@
     },
 
     'drfuzz': { 'gn_args': 'use_drfuzz=true' },
 
     'drmemory': {
       'gn_args': 'is_component_build=true enable_iterator_debugging=false',
       'gyp_defines': 'component=shared_library build_for_tool=drmemory',
     },
   },
 }