tree cef32e7ddffeb39d36894ac6ad7350a8de229164
parent 8c01622348c679409c945f7839570686bfc33e19
author bnc <bnc@google.com> 1566493063 -0700
committer Copybara-Service <copybara-worker@google.com> 1566495567 -0700

Signal error on duplicate SETTINGS identifiers.

See https://quicwg.org/base-drafts/draft-ietf-quic-http.html#frame-settings,
with proposed clarification at https://github.com/quicwg/base-drafts/pull/2979.

gfe-relnote: n/a, change to QUIC v99-only code.  Protected by existing disabled gfe2_reloadable_flag_quic_enable_version_99.
PiperOrigin-RevId: 264857966
Change-Id: I6bcd0f70cb52d897d465fb89f9937ab4a3ea093f