Detect TSAN instead of relying on #ifdef THREAD_SANITIZER.

gyp/common_conditions.gypi

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # conditions used in both common.gypi and skia.gyp in chromium
 #
 {
   'defines': [
     'SK_ALLOW_STATIC_GLOBAL_INITIALIZERS=<(skia_static_initializers)',
@@ skipping 446 matching lines @@
           [ 'skia_sanitizer', {
             'cflags_cc!': [ '-fno-rtti' ],                        # vptr needs rtti
             'cflags': [
               '-fsanitize=<(skia_sanitizer)',                     # Turn on sanitizers.
               '-fno-sanitize-recover=<(skia_sanitizer)',          # Make any failure fatal.
               '-fsanitize-blacklist=<(skia_sanitizer_blacklist)', # Compile in our blacklist.
               '-include <(skia_sanitizer_blacklist)',             # Make every .cpp depend on it.
             ],
             'ldflags': [ '-fsanitize=<(skia_sanitizer)' ],
             'conditions' : [
-              [ 'skia_sanitizer == "thread"', {
-                'defines': [ 'THREAD_SANITIZER' ],
-              }],
               [ 'skia_sanitizer == "memory"', {
                 'cflags': [
                     '-O1',
                     '-fsanitize-memory-track-origins',
                 ],
               }],
             ],
           }],
           [ 'skia_clang_build', {
             'cflags_cc': [
@@ skipping 221 matching lines @@
           'LD_RUNPATH_SEARCH_PATHS': ['@executable_path/.'],
       },
     }],
 
   ], # end 'conditions'
   # The Xcode SYMROOT must be at the root. See build/common.gypi in chromium for more details
   'xcode_settings': {
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }