And add a reasonable timeout to tests.
Change-Id: I362d44f2a799562d236a80f5c35d50d93e8d094a
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/56769
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: David Neto <dneto@google.com>