Compression Dictionary - Updated Chrome Origin Trial

[Patrick Meenan <[e-mail]>]

FYI, Chrome 123 (currently in beta) has been updated to implement the
latest compression dictionary transport draft (03).

If you're already experimenting with it you'll need to register for a new
token
<https://developer.chrome.com/origintrials/#/view_trial/3693514644397228033>
(new trial since there were header changes since the first trial).

The previous trial was from before it was adopted by the working group so
there were a fair number of changes (all for the better, thank you).

- "Sec-Available-Dictionary" changed to "Available-Dictionary"
- The format of "Available-Dictionary" is now a SF byte stream field
(base-64 encoding of the dictionary hash, surrounded by colons) instead of
hex string
- "sbr" changed to "br-d"
- "match" is now a URLPattern (though might not require any changes)
- ttl is gone and now uses the resource expiration time
- The server can provide an "id" which is echoed as "Dictionary-ID" by the
client in future requests (instead of needing to use the dictionary hash as
a lookup key, the string is opaque to the client)
- The server needs to send "Content-Dictionary" in the response header with
the hash of the dictionary used (must match the "Available-Dictionary" from
the request)
- "match-dest" is now supported so you can do something like
match-dest="document"
and have the dictionary only be used for document requests

Thanks,

-Pat