mb: Remove a redundant mixin

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 1185 matching lines @@
 
     'gn_release_trybot': [
       'gn', 'release_trybot',
     ],
 
     'gn_release_trybot_x64': [
       'gn', 'release_trybot', 'x64',
     ],
 
     'gn_windows_analyze': [
-      'gn', 'no_symbols', 'disable_precompiled_headers',
-      'shared', 'x86', 'win_analyze',
+      'gn', 'no_symbols', 'no_pch', 'shared', 'x86', 'win_analyze',
     ],
 
     'gn_ubsan_vptr_release_bot': [
       'gn', 'ubsan_vptr', 'ubsan_no_recover_hack', 'release_bot',
     ],
 
     'gyp_asan_edge_fuzzer_v8_heap_chromeos_codecs_release_bot_hybrid': [
       'gyp', 'asan', 'edge', 'fuzzer', 'v8_heap', 'chromeos_codecs',
       'release_bot', 'hybrid',
     ],
@@ skipping 800 matching lines @@
 
     'debug_trybot': {
       'mixins': ['debug_bot_minimal_symbols'],
     },
 
     'disable_nacl': {
       'gn_args': 'enable_nacl=false',
       'gyp_defines': 'disable_nacl=1',
     },
 
-    'disable_precompiled_headers': {
-      'gn_args': 'disable_precompiled_headers=true',
-      'gyp_defines': 'chromium_win_pch=0',
-    },
-
     'edge': {
       'gn_args': 'sanitizer_coverage_flags="edge"',
       'gyp_defines': 'sanitizer_coverage=edge',
     },
 
     # This mixin is used to force configs that use it to fail. It
     # is used in two cases: when we have bots that we haven't looked
     # at yet and don't know whether they need MB or not, and for bots
     # that are test-only and should never run MB.
     'error': {
@@ skipping 259 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',
     },
   },
 }