Add WSL marker

Change-Id: I9d3f61e59556d63b19d1db7967dfb7fef901dc7a
Reviewed-on: https://chromium-review.googlesource.com/c/external/github.com/WebKit/JetStream/+/6422137
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
1 file changed