Actually flip the chromium.mac Mac builders to GN after r400895.

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 329 matching lines @@
       'UBSan vptr Release': 'gyp_ubsan_vptr_edge_release_bot',
       'Win ASan Release Coverage':
         'gyp_asan_edge_fuzzer_v8_heap_release_bot_x86',
       'Win ASan Release Media':
         'gyp_asan_fuzzer_v8_heap_chrome_with_codecs_release_bot_x86',
       'Win ASan Release': 'gyp_asan_fuzzer_v8_heap_release_bot_x86',
       'Win SyzyASAN LKGR': 'gyp_syzyasan_no_pch_win_z7_x86',
     },
 
     'chromium.mac': {
-      'Mac Builder': 'swarming_gpu_tests_gyp_release_bot',
-      'Mac Builder (dbg)': 'swarming_gyp_debug_bot',
+      'Mac Builder': 'swarming_gpu_tests_gn_release_bot',
+      'Mac Builder (dbg)': 'swarming_gn_debug_bot',
       'Mac GN (dbg)': 'gn_debug_bot',
       'Mac GN': 'gn_release_bot',
       'Mac10.10 Tests': 'none',
       'Mac10.11 Tests': 'none',
       'Mac10.9 Tests (dbg)': 'none',
       'Mac10.9 Tests': 'none',
       'ios-device': 'ios_gyp',
       'ios-device-gn': 'ios_gn',
       'ios-simulator': 'ios_gyp',
       'ios-simulator-gn': 'ios_gn',
@@ skipping 1311 matching lines @@
     ],
 
     'swarming_gpu_tests_gn_release_trybot': [
       'swarming', 'gpu_tests', 'gn', 'release_trybot',
     ],
 
     'swarming_gpu_tests_gn_release_trybot_x86': [
       'swarming', 'gpu_tests', 'gn', 'release_trybot', 'x86',
     ],
 
+    'swarming_gpu_tests_gn_release_bot': [
+      'swarming', 'gpu_tests', 'gn', 'release_bot',
+    ],
+
     'swarming_gpu_tests_gyp_release_bot': [
       'swarming', 'gpu_tests', 'gyp', 'release_bot',
     ],
 
     'swarming_gpu_tests_gyp_release_bot_minimal_symbols_x86': [
       'swarming', 'gpu_tests', 'gyp', 'release_bot', 'minimal_symbols', 'x86',
     ],
 
     'swarming_gpu_tests_gyp_release_bot_x86': [
       'swarming', 'gpu_tests', 'gyp', 'release_bot',
@@ skipping 130 matching lines @@
     'swarming_gyp_clang_tot_official_minimal_symbols_static_release_x64': [
       'swarming', 'gyp', 'clang_tot', 'official', 'minimal_symbols', 'static',
       'release', 'x64',
     ],
 
     'swarming_gyp_clang_tot_official_minimal_symbols_static_release_x86': [
       'swarming', 'gyp', 'clang_tot', 'official', 'minimal_symbols', 'static',
       'release', 'x86',
     ],
 
-    'swarming_gyp_debug_bot': [
-      'swarming', 'gyp', 'debug_bot',
-    ],
-
     'swarming_gn_release_trybot_arm': [
       'swarming', 'gn', 'release_trybot', 'arm', 'crosscompile',
     ],
 
     'swarming_gyp_syzyasan_release_trybot_x86': [
       'swarming', 'gyp', 'syzyasan', 'release_trybot', 'x86',
     ],
 
     'swarming_tsan_disable_nacl_gn_release_bot': [
       'swarming', 'tsan', 'disable_nacl', 'gn', 'release_bot',
@@ skipping 460 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',
     },
   },
 }