Disable LSAN (LeakSanitizer) on Windows.

LSAN doesn't currently support Windows [1].

This fixes win-asan trybot breakage caused by
https://crrev.com/c/1590404.

[1]
https://github.com/google/sanitizers/wiki/AddressSanitizerWindowsPort#lsan

Cq-Include-Trybots: luci.chromium.try:win-asan
Change-Id: I62e5ee13bb0d83a414e4a0456e9ffa27129ae28d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1658436
Commit-Queue: Caleb Raitto <[email protected]>
Reviewed-by: John Budorick <[email protected]>
Cr-Commit-Position: refs/heads/master@{#669078}
diff --git a/tools/mb/mb.py b/tools/mb/mb.py
index 150c26a..5bd9ad0 100755
--- a/tools/mb/mb.py
+++ b/tools/mb/mb.py
@@ -1251,7 +1251,9 @@
         './' + str(executable) + executable_suffix,
         '--test-launcher-bot-mode',
         '--asan=%d' % asan,
-        '--lsan=%d' % asan,  # Enable lsan when asan is enabled.
+        # Enable lsan when asan is enabled except on Windows where LSAN isn't
+        # supported.
+        '--lsan=%d' % (asan and not is_win),
         '--msan=%d' % msan,
         '--tsan=%d' % tsan,
         '--cfi-diag=%d' % cfi_diag,
@@ -1262,7 +1264,9 @@
           './' + str(executable) + executable_suffix,
           '--test-launcher-bot-mode',
           '--asan=%d' % asan,
-          '--lsan=%d' % asan,  # Enable lsan when asan is enabled.
+          # Enable lsan when asan is enabled except on Windows where LSAN isn't
+          # supported.
+          '--lsan=%d' % (asan and not is_win),
           '--msan=%d' % msan,
           '--tsan=%d' % tsan,
           '--cfi-diag=%d' % cfi_diag,