Make SyzyAsan depend on 'syzyasan' GYP flag instead of 'asan==1 and OS=="win"'

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 328 matching lines @@
       'clang_use_chrome_plugins%': 1,
 
       # Enable building with ASAN (Clang's -fsanitize=address option).
       # -fsanitize=address only works with clang, but asan=1 implies clang=1
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/addresssanitizer
       'asan%': 0,
       # Enable coverage gathering instrumentation in ASan. This flag also
       # controls coverage granularity (experimental).
       'asan_coverage%': 0,
 
+      # Enable building with SyzyAsan.
+      # See https://code.google.com/p/sawbuck/wiki/SyzyASanHowTo
+      'syzyasan%': 0,
+
       # Enable building with LSan (Clang's -fsanitize=leak option).
       # -fsanitize=leak only works with clang, but lsan=1 implies clang=1
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/leaksanitizer
       'lsan%': 0,
 
       # Enable building with TSAN (Clang's -fsanitize=thread option).
       # -fsanitize=thread only works with clang, but tsan=1 implies clang=1
       # See http://clang.llvm.org/docs/ThreadSanitizer.html
       'tsan%': 0,
       'tsan_blacklist%': '<(PRODUCT_DIR)/../../tools/valgrind/tsan_v2/ignores.txt',
@@ skipping 555 matching lines @@
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'input_speech%': '<(input_speech)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'mac_want_real_dsym%': '<(mac_want_real_dsym)',
     'asan%': '<(asan)',
     'asan_coverage%': '<(asan_coverage)',
+    'syzyasan%': '<(syzyasan)',
     'lsan%': '<(lsan)',
     'msan%': '<(msan)',
     'msan_blacklist%': '<(msan_blacklist)',
     'tsan%': '<(tsan)',
     'tsan_blacklist%': '<(tsan_blacklist)',
     'use_instrumented_libraries%': '<(use_instrumented_libraries)',
     'use_custom_libcxx%': '<(use_custom_libcxx)',
     'clang_type_profiler%': '<(clang_type_profiler)',
     'order_profiling%': '<(order_profiling)',
     'order_text_section%': '<(order_text_section)',
@@ skipping 836 matching lines @@
       }],
       ['enable_task_manager==1', {
         'grit_defines': ['-D', 'enable_task_manager'],
       }],
       ['clang_use_chrome_plugins==1 and OS!="win"', {
         'clang_chrome_plugins_flags': [
           '<!@(<(DEPTH)/tools/clang/scripts/plugin_flags.sh)'
         ],
       }],
 
+      ['asan==1 and OS=="win"', {
+        # TODO(hans): Remove once users set syzyasan (crbug.com/343960).
+        'syzyasan%': 1,
+      }],
       ['asan==1 and OS!="win"', {
+        # TODO(hans): Windows should use Clang-based ASan (crbug.com/343960).
         'clang%': 1,
       }],
       ['asan==1 and OS=="mac"', {
         # TODO(glider): we do not strip ASan binaries until the dynamic ASan
         # runtime is fully adopted. See http://crbug.com/242503.
         'mac_strip_release': 0,
       }],
       ['lsan==1', {
         'clang%': 1,
       }],
@@ skipping 523 matching lines @@
       ['use_openssl==1', {
         'defines': [
           'USE_OPENSSL=1',
         ],
       }],
       ['enable_eglimage==1', {
         'defines': [
           'ENABLE_EGLIMAGE=1',
         ],
       }],
-      ['asan==1 and OS=="win"', {
-        # Since asan on windows uses Syzygy, we need /PROFILE turned on to
-        # produce appropriate pdbs.
+      ['syzyasan==1', {
+        # SyzyAsan needs /PROFILE turned on to produce appropriate pdbs.
         'msvs_settings': {
           'VCLinkerTool': {
             'Profile': 'true',
           },
         },
         'defines': [
             'ADDRESS_SANITIZER',
             'MEMORY_TOOL_REPLACES_ALLOCATOR',
         ],
-      }],  # asan==1 and OS=="win"
+      }],
       ['OS=="win"', {
         'defines': [
           '__STD_C',
           '_CRT_SECURE_NO_DEPRECATE',
           '_SCL_SECURE_NO_DEPRECATE',
           # This define is required to pull in the new Win8 interfaces from
           # system headers like ShObjIdl.h.
           'NTDDI_VERSION=0x06020000',
           # This is required for ATL to use XP-safe versions of its functions.
           '_USING_V110_SDK71_',
@@ skipping 2408 matching lines @@
             'msvs_settings': {
               'VCLinkerTool': {
                 'AdditionalOptions': [
                   '/safeseh',
                   '/dynamicbase',
                   '/ignore:4199',
                   '/ignore:4221',
                   '/nxcompat',
                 ],
                 'conditions': [
-                  ['asan==0', {
+                  ['syzyasan==0', {
                     'AdditionalOptions': ['/largeaddressaware'],
                   }],
                 ],
               },
             },
           },
           'x64_Base': {
             'msvs_settings': {
               'VCLinkerTool': {
                 'AdditionalOptions': [
@@ skipping 134 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }