Disable DCHECKs on linux_chromium_msan_rel_ng.

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 737 matching lines @@
       'linux_chromium_clobber_rel_ng': 'gn_release_trybot',
       'linux_chromium_compile_dbg_32_ng': 'swarming_gn_debug_trybot_x86',
       'linux_chromium_compile_dbg_ng': 'swarming_gn_debug_trybot',
       'linux_chromium_compile_rel_ng': 'swarming_gn_release_trybot',
       'linux_chromium_dbg_32_ng': 'swarming_gn_debug_trybot_x86',
       'linux_chromium_dbg_ng': 'swarming_gn_debug_trybot',
       'linux_chromium_gn_chromeos_dbg': 'chromeos_gn_debug_bot',
       'linux_chromium_gn_chromeos_rel': 'chromeos_ozone_gn_release_trybot',
       'linux_chromium_gn_chromeos_variable': 'findit',
       'linux_chromium_gn_upload': 'gn_linux_upload',
-      'linux_chromium_msan_rel_ng': 'swarming_msan_gn_release_trybot',
+
+      # This is intentionally a release_bot and not a release_trybot;
+      # enabling DCHECKs seems to cause flaky failures that don't show up
+      # on the continuous builder.
+      'linux_chromium_msan_rel_ng': 'swarming_msan_gn_release_bot',
+
       'linux_chromium_rel_ng': 'swarming_gpu_tests_gn_release_trybot',
       'linux_chromium_tsan_rel_ng':
         'swarming_tsan_disable_nacl_gn_release_trybot',
       'linux_chromium_variable': 'findit',
       'linux_chromium_variable_32': 'findit',
       'linux_chromium_variable_chrome': 'findit',
       'linux_chromium_variable_clobber': 'findit',
       'linux_chromium_variable_32_chrome': 'findit',
       'linux_chromium_variable_32_clobber': 'findit',
       'linux_chromium_webkit_asan_variable': 'findit',
@@ skipping 1094 matching lines @@
     ],
 
     'swarming_tsan_disable_nacl_gn_release_trybot': [
       'swarming', 'tsan', 'disable_nacl', 'gn', 'release_trybot',
     ],
 
     'swarming_msan_gn_release_bot': [
       'swarming', 'msan', 'gn', 'release_bot',
     ],
 
-    'swarming_msan_gn_release_trybot': [
-      'swarming', 'msan', 'gn', 'release_trybot',
-    ],
-
     'win_clang_debug_bot': [
       'gn', 'clang', 'debug_bot_minimal_symbols',
     ],
   },
 
   # This is a dict mapping a given 'mixin' name to a dict of settings that
   # mb should use. See //tools/mb/docs/user_guide.md for more information.
   'mixins': {
     # We build Android with codecs on most bots to ensure maximum test
     # coverage, but use 'android_without_codecs' on bots responsible for
@@ skipping 440 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',
     },
   },
 }