deprecate -FLAGS_quic_reloadable_flag_quic_disable_version_34 and remove support for QUIC v34.

net/quic/core/quic_session.cc

Index: net/quic/core/quic_session.cc
diff --git a/net/quic/core/quic_session.cc b/net/quic/core/quic_session.cc
index 0a18e560648d2c97f0f612b66b5acd3161c18d2f..dba6c46b25c5e382a541af587ff1829e66c7e457 100644
--- a/net/quic/core/quic_session.cc
+++ b/net/quic/core/quic_session.cc
@@ -436,10 +436,8 @@ bool QuicSession::IsCryptoHandshakeConfirmed() {
 void QuicSession::OnConfigNegotiated() {
   connection_->SetFromConfig(config_);
 
-  const QuicVersion version = connection()->version();
   uint32_t max_streams = 0;
-  if (version > QUIC_VERSION_34 &&
-      config_.HasReceivedMaxIncomingDynamicStreams()) {
+  if (config_.HasReceivedMaxIncomingDynamicStreams()) {
     max_streams = config_.ReceivedMaxIncomingDynamicStreams();
   } else {
     max_streams = config_.MaxStreamsPerConnection();
@@ -467,25 +465,18 @@ void QuicSession::OnConfigNegotiated() {
     }
   }
 
-  if (version <= QUIC_VERSION_34) {
-    // A small number of additional incoming streams beyond the limit should be
-    // allowed. This helps avoid early connection termination when FIN/RSTs for
-    // old streams are lost or arrive out of order.
-    // Use a minimum number of additional streams, or a percentage increase,
-    // whichever is larger.
-    uint32_t max_incoming_streams =
-        std::max(max_streams + kMaxStreamsMinimumIncrement,
-                 static_cast<uint32_t>(max_streams * kMaxStreamsMultiplier));
-    set_max_open_incoming_streams(max_incoming_streams);
-  } else {
-    uint32_t max_incoming_streams_to_send =
-        config_.GetMaxIncomingDynamicStreamsToSend();
-    uint32_t max_incoming_streams =
-        std::max(max_incoming_streams_to_send + kMaxStreamsMinimumIncrement,
-                 static_cast<uint32_t>(max_incoming_streams_to_send *
-                                       kMaxStreamsMultiplier));
-    set_max_open_incoming_streams(max_incoming_streams);
-  }
+  // A small number of additional incoming streams beyond the limit should be
+  // allowed. This helps avoid early connection termination when FIN/RSTs for
+  // old streams are lost or arrive out of order.
+  // Use a minimum number of additional streams, or a percentage increase,
+  // whichever is larger.
+  uint32_t max_incoming_streams_to_send =
+      config_.GetMaxIncomingDynamicStreamsToSend();
+  uint32_t max_incoming_streams =
+      std::max(max_incoming_streams_to_send + kMaxStreamsMinimumIncrement,
+               static_cast<uint32_t>(max_incoming_streams_to_send *
+                                     kMaxStreamsMultiplier));
+  set_max_open_incoming_streams(max_incoming_streams);
 
   if (config_.HasReceivedInitialStreamFlowControlWindowBytes()) {
     // Streams which were created before the SHLO was received (0-RTT