Update Token Binding code to match latest draft draft-ietf-tokbind-protocol-04

BUG=467312

Review URL: https://codereview.chromium.org/1636453004

Cr-Original-Commit-Position: refs/heads/master@{#372198}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 47d408a4847886b442365a41ef8281ca99de0812
3 files changed