Add tests for Headless Linux bot

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': {
     # Take care when changing any of these builders to ensure that you do not
@@ skipping 179 matching lines @@
         'swarming_gyp_clang_shared_release_bot_minimal_symbols_x86',
       'CrWinClang(shared) tester': 'none',
       'CrWinClang64 tester': 'none',
       'CrWinClang64(dbg) tester': 'none',
       'CrWinClang64(dbg)': 'win_clang_debug_bot',
       'CrWinClang64(dll) tester': 'none',
       'CrWinClangLLD tester': 'none',
       'CrWinClangLLD64 tester': 'none',
       'CrWinClngLLD64dbg tester': 'none',
       'CrWinClngLLDdbg tester': 'none',
+      'Headless Linux (dbg)':
+        '//build/args/bots/chromium.fyi/headless_linux_dbg.gn',
       'LTO Linux Perf': 'gn_official_goma_lto',
       'Libfuzzer Upload Linux ASan': 'gn_release_libfuzzer_asan',
       'Libfuzzer Upload Linux MSan': 'gn_release_libfuzzer_msan',
       'Libfuzzer Upload Linux UBSan': 'gn_release_libfuzzer_ubsan',
       'Linux ARM': 'swarming_gyp_release_bot_arm',
       'Site Isolation Linux': 'gn_release_trybot',
       'Site Isolation Win': 'gyp_release_trybot_x64',
       'Vista Tests (dbg)(1)': 'none',
       'Vista Tests (dbg)(2)': 'none',
       'WebKit Linux - TraceWrappables': 'swarming_gn_release_bot_x64',
@@ skipping 1628 matching lines @@
       'gn_args': 'is_component_build=true enable_iterator_debugging=false',
       'gyp_defines': 'component=shared_library build_for_tool=drmemory',
     },
 
     'valgrind': {
       # TODO: add gn_args for 'build_for_tool=memcheck'
       'gyp_defines': 'build_for_tool=memcheck',
     }
   },
 }