Add token binding negotiation to QUIC

Add token binding negotiation to QUIC

This adds a tag (TBKP) to the SCFG and CHLO messages containing a taglist as a value of the supported token binding key parameters (P256 is currently the only supported param). This replaces the TLS token binding negotiation extension as part of the broader Token Binding spec when done over QUIC.

Token binding negotiation is off by default - it must be turned on server-side in QuicCryptoServerConfig::ConfigOptions and client side in QuicCryptoClientConfig. If it is enabled, the application layer using QUIC must handle the rest of the Token Binding protocol.

More information (including links to the Token Binding specs) is in this doc: https://docs.google.com/document/d/12eKfkdC7g5IGUCtghzg7Wi__qiEkY65fX09n8sjLtHg/edit?pli=1#heading=h.y8fw05yhvdsg

Merge internal change: 107277639

R=rch@chromium.org
BUG=

[Ryan Hamilton, 2015-11-11 17:56:54]

lgtm