Make QUIC version negotiation stateless. The QUIC dispatcher now detects version mismatch before cr…

net/quic/quic_framer.cc

Index: net/quic/quic_framer.cc
diff --git a/net/quic/quic_framer.cc b/net/quic/quic_framer.cc
index 48248b1a3f83a4f82788f78fa2034bacfb7cb52f..ac58d57ae3cd97922e2cd5008a9635d456e0860b 100644
--- a/net/quic/quic_framer.cc
+++ b/net/quic/quic_framer.cc
@@ -975,6 +975,7 @@ bool QuicFramer::ProcessPublicHeader(QuicDataReader* reader,
     // If the version from the new packet is the same as the version of this
     // framer, then the public flags should be set to something we understand.
     // If not, this raises an error.
+    last_version_tag_ = version_tag;
     QuicVersion version = QuicTagToQuicVersion(version_tag);
     if (version == quic_version_ && public_flags > PACKET_PUBLIC_FLAGS_MAX) {
       set_detailed_error("Illegal public flags value.");