[WPT/common/security-features] Add formatter of spec.src.json

Bug: 906850
Change-Id: I486eef6697a7ef5ff1360549321236add8e1c75b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1717499
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#681079}
4 files changed