GN: Implement is_lsan, is_tsan and is_msan.

build/config/BUILDCONFIG.gn

 # Copyright (c) 2013 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.
 
 # =============================================================================
 # BUILD FLAGS
 # =============================================================================
 #
 # This block lists input arguments to the build, along with their default
 # values. GN requires listing them explicitly so it can validate input and have
@@ skipping 355 matching lines @@
   _default_optimization_config = "//build/config/compiler:optimize"
 }
 _native_compiler_configs += [ _default_optimization_config ]
 
 # If it wasn't manually set, set to an appropriate default.
 if (symbol_level == -1) {
   # Linux is slowed by having symbols as part of the target binary, whereas
   # Mac and Windows have them separate, so in Release Linux, default them off.
   if (is_debug || !is_linux) {
     symbol_level = 2
+  } else if (is_asan || is_lsan || is_tsan || is_msan) {
+    # Sanitizers require symbols for filename suppressions to work.
+    symbol_level = 1
   } else {
     symbol_level = 0
   }
 }
 
 # Symbol setup.
 if (symbol_level == 2) {
   _default_symbols_config = "//build/config/compiler:symbols"
 } else if (symbol_level == 1) {
   _default_symbols_config = "//build/config/compiler:minimal_symbols"
@@ skipping 340 matching lines @@
       }
       if (defined(invoker.testonly)) {
         testonly = invoker.testonly
       }
       if (defined(invoker.visibility)) {
         visibility = invoker.visibility
       }
     }
   }
 }