Only use sanitizers with default toolchain on Windows as well.

build/config/sanitizers/sanitizers.gni

Index: build/config/sanitizers/sanitizers.gni
diff --git a/build/config/sanitizers/sanitizers.gni b/build/config/sanitizers/sanitizers.gni
index 16117223110eed8bbd8c2669aeae1e05267de8ad..ba1aec4833e0fc3d2868e92d8d47345743669e43 100644
--- a/build/config/sanitizers/sanitizers.gni
+++ b/build/config/sanitizers/sanitizers.gni
@@ -90,6 +90,30 @@ declare_args() {
   sanitizer_coverage_flags = ""
 }
 
+# Disable sanitizers for non-default toolchains.
+if (current_toolchain != default_toolchain) {
+  is_asan = false
+  is_cfi = false
+  is_lsan = false
+  is_msan = false
+  is_syzyasan = false
+  is_tsan = false
+  is_ubsan = false
+  is_ubsan_null = false
+  is_ubsan_no_recover = false
+  is_ubsan_security = false
+  is_ubsan_vptr = false
+  msan_track_origins = 0
+  sanitizer_coverage_flags = ""
+  use_cfi_diag = false
+  use_custom_libcxx = false
+  use_drfuzz = false
+  use_libfuzzer = false
+  use_prebuilt_instrumented_libraries = false
+  use_locally_built_instrumented_libraries = false
+  use_sanitizer_coverage = false
+}
+
 # Args that are in turn dependent on other args must be in a separate
 # declare_args block. User overrides are only applied at the end of a
 # declare_args block.