Re-commit "win: Set is_clang=true by default" over the weekend.

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 .pyl, or "Python Literal", file. You can treat it just like a
 # .json file, with the following exceptions:
 # * all keys must be quoted (use single quotes, please);
 # * comments are allowed, using '#' syntax; and
 # * trailing commas are allowed.
 
@@ skipping 1024 matching lines @@
 
     'chromeos_with_codecs_release_trybot': [
       'chromeos_with_codecs', 'x11_cros', 'release_trybot',
     ],
 
     'clang_debug_trybot_x86': [
       'clang', 'debug_trybot', 'x86',
     ],
 
     'clang_debug_bot_minimal_symbols_x86': [
-      'clang', 'debug_bot', 'minimal_symbols', 'x86',
+      # Now that the default win bots use clang, use a "clang" bot to make sure
+      # things stay compilable with msvc. TODO(thakis): Having a "clang" bot
+      # check that is very confusing, so rename the bot to "msvc".
+      'no_clang', 'debug_bot', 'minimal_symbols', 'x86',
     ],
 
     'clang_release_bot_minimal_symbols_x86': [
       'clang', 'release_bot', 'minimal_symbols', 'x86',
     ],
 
     'clang_minimal_symbols_shared_release_bot_x86_dcheck': [
-      'clang', 'minimal_symbols', 'shared_release_bot', 'x86', 'dcheck_always_on',
+      # Now that the default win bots use clang, use a "clang" bot to make sure
+      # things stay compilable with msvc. TODO(thakis): Having a "clang" bot
+      # check that is very confusing, so rename the bot to "msvc".
+      'no_clang', 'minimal_symbols', 'shared_release_bot', 'x86', 'dcheck_always_on',
     ],
 
     'clang_official_release_bot_minimal_symbols': [
-      'clang', 'official', 'release_bot', 'minimal_symbols',
+      # Now that the default win bots use clang, use a "clang" bot to make sure
+      # things stay compilable with msvc. TODO(thakis): Having a "clang" bot
+      # check that is very confusing, so rename the bot to "msvc".
+      'no_clang', 'official', 'release_bot', 'minimal_symbols',
     ],
 
     'clang_official_release_bot_minimal_symbols_x86': [
-      'clang', 'official', 'release_bot', 'minimal_symbols', 'x86',
+      # Now that the default win bots use clang, use a "clang" bot to make sure
+      # things stay compilable with msvc. TODO(thakis): Having a "clang" bot
+      # check that is very confusing, so rename the bot to "msvc".
+      'no_clang', 'official', 'release_bot', 'minimal_symbols', 'x86',
     ],
 
     'clang_official_optimize_release_bot_minimal_symbols_x86': [
       'clang', 'official_optimize', 'release_bot', 'minimal_symbols', 'x86',
     ],
 
     'clang_official_release_trybot': [
       'clang', 'official', 'release_trybot',
     ],
 
     'clang_official_release_trybot_x86': [
       'clang', 'official', 'release_trybot', 'x86',
     ],
 
     'clang_shared_release_bot_dcheck': [
-      'clang', 'shared_release_bot', 'dcheck_always_on',
+      # Now that the default win bots use clang, use a "clang" bot to make sure
+      # things stay compilable with msvc. TODO(thakis): Having a "clang" bot
+      # check that is very confusing, so rename the bot to "msvc".
+      'no_clang', 'shared_release_bot', 'dcheck_always_on',
     ],
 
     'clang_tot_asan_lsan_static_release': [
       'clang_tot', 'asan', 'lsan', 'static', 'release',
     ],
 
     'clang_tot_edge_ubsan_no_recover_hack_static_release': [
       'clang_tot', 'edge', 'ubsan_no_recover_hack', 'static', 'release',
     ],
 
@@ skipping 402 matching lines @@
 
     'v8_future_debug_bot': [
       'v8_future', 'debug_bot',
     ],
 
     'v8_future_release_bot': [
       'v8_future', 'release_bot',
     ],
 
     'win_clang_debug_bot': [
-      'clang', 'debug_bot', 'minimal_symbols',
+      # Now that the default win bots use clang, use a "clang" bot to make sure
+      # things stay compilable with msvc. TODO(thakis): Having a "clang" bot
+      # check that is very confusing, so rename the bot to "msvc".
+      'no_clang', 'debug_bot', 'minimal_symbols',
     ],
 
     'windows_analyze': [
       'no_symbols', 'no_pch', 'shared', 'x86', 'win_analyze',
     ],
   },
 
   # 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': {
@@ skipping 69 matching lines @@
     'cfi_full': {
       'gn_args': 'use_cfi_cast=true',
       'mixins': ['cfi'],
     },
 
     'cfi_diag': {
       'gn_args': 'use_cfi_diag=true',
     },
 
     'chrome_pgo_phase_1': {
-      'gn_args': 'chrome_pgo_phase=1',
+      'gn_args': 'chrome_pgo_phase=1 is_clang=false',
     },
 
     'chrome_pgo_phase_2': {
-      'gn_args': 'chrome_pgo_phase=2',
+      'gn_args': 'chrome_pgo_phase=2 is_clang=false',
     },
 
     'chrome_with_codecs': {
       'mixins': ['ffmpeg_branding_chrome', 'proprietary_codecs'],
     },
 
     'chromeos': {
       'gn_args': 'target_os="chromeos"',
     },
 
@@ skipping 255 matching lines @@
 
     'static': {
       'gn_args': 'is_component_build=false',
     },
 
     'system_gbm_libdrm': {
       'gn_args': 'use_system_libdrm=true use_system_minigbm=true',
     },
 
     'syzyasan': {
-      'gn_args': 'is_syzyasan=true',
+      # TODO(thakis): Figure out SyzyASan + clang story.
+      'gn_args': 'is_syzyasan=true is_clang=false',
     },
 
     'thin_lto': {
       'gn_args': 'use_thin_lto=true',
       'mixins': ['lto'],
     },
 
     'tsan': {
       'gn_args': 'is_tsan=true',
     },
@@ skipping 36 matching lines @@
 
     'x64': {
       'gn_args': 'target_cpu="x64"',
     },
 
     'x86': {
       'gn_args': 'target_cpu="x86"',
     },
   },
 }