webauthn: Add a WPT for the clientDataJSON serialization.
WebAuthn specifies[1] that this JSON must be serialized in a precise
order. WPTs should test that.
[1] https://www.w3.org/TR/webauthn-2/#clientdatajson-serialization
Change-Id: I8038909c2e55b1de699de6d450e2d9efdc72258f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5794170
Commit-Queue: Adam Langley agl@chromium.org
Auto-Submit: Adam Langley agl@chromium.org
Reviewed-by: Nina Satragno nsatragno@chromium.org
Cr-Commit-Position: refs/heads/main@{#1345069}