Add Syzygy support to Windows GN build.

build/config/allocator.gni

 # Copyright 2014 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.
 
+import("//build/config/sanitizers/sanitizers.gni")
+
 # TODO(GYP): Make tcmalloc work on win.
 if (is_android || current_cpu == "mipsel" || is_mac || is_ios || is_asan ||
-    is_lsan || is_tsan || is_msan || is_win) {
+    is_lsan || is_tsan || is_msan || is_win || is_syzyasan) {
   _default_allocator = "none"
 } else {
   _default_allocator = "tcmalloc"
 }
 
 declare_args() {
   # Memory allocator to use. Set to "none" to use default allocator.
   use_allocator = _default_allocator
 }