Will be used by GN to know the outputs of the generate cache step.
Change-Id: Iae09477fb355eac41ff9b2204605f46ed78e08ec
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/110620
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>