Pulls license information from subfiles into a single LICENSE file
so that Chromium's tools/licenses.py can read it.
Change-Id: I3fbbca3922193eb5fec361fef833ffc3cfdc9e45
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/100500
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Auto-Submit: Austin Eng <enga@chromium.org>