relnote: Close the QUIC connection when a packet is about to be sent out

net/quic/quic_connection.cc

Index: net/quic/quic_connection.cc
diff --git a/net/quic/quic_connection.cc b/net/quic/quic_connection.cc
index f663111c2cdaf13369d6d438ac02004586c5511f..682a0a556d35b1a296def180be80da4b9156fb51 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -1615,6 +1615,16 @@ bool QuicConnection::WritePacket(QueuedPacket* packet) {
 }
 
 bool QuicConnection::WritePacketInner(QueuedPacket* packet) {
+  if (FLAGS_quic_close_connection_out_of_order_sending &&
+      packet->serialized_packet.packet_number <
+          sent_packet_manager_.largest_sent_packet()) {
+    LOG(DFATAL) << "Attempt to write packet:"
+                << packet->serialized_packet.packet_number
+                << " after:" << sent_packet_manager_.largest_sent_packet();
+    SendConnectionCloseWithDetails(QUIC_INTERNAL_ERROR,
+                                   "Packet written out of order.");
+    return true;
+  }
   if (ShouldDiscardPacket(*packet)) {
     ++stats_.packets_discarded;
     return true;