short circuit QUIC packets to packet buffer if there is already a CHLO on same connection buffered …

net/tools/quic/quic_dispatcher.cc

Index: net/tools/quic/quic_dispatcher.cc
diff --git a/net/tools/quic/quic_dispatcher.cc b/net/tools/quic/quic_dispatcher.cc
index 0d558694418f84c74ddabd2696a2d179cfd53a7f..b43b8e1664fe6018ad07090588982f900da4e52d 100644
--- a/net/tools/quic/quic_dispatcher.cc
+++ b/net/tools/quic/quic_dispatcher.cc
@@ -273,6 +273,12 @@ bool QuicDispatcher::OnUnauthenticatedPublicHeader(
     return false;
   }
 
+  if (FLAGS_quic_buffer_packets_after_chlo &&
+      buffered_packets_.HasChloForConnection(connection_id)) {
+    BufferEarlyPacket(connection_id);
+    return false;
+  }
+
   if (!OnUnauthenticatedUnknownPublicHeader(header)) {
     return false;
   }
@@ -692,7 +698,10 @@ void QuicDispatcher::ProcessChlo() {
       new_sessions_allowed_per_event_loop_ <= 0) {
     // Can't create new session any more. Wait till next event loop.
     if (!buffered_packets_.HasChloForConnection(current_connection_id_)) {
-      // Only buffer one CHLO per connection.
+      // Only buffer one CHLO per connection. Remove this condition check when
+      // --gfe2_reloadable_flag_quic_buffer_packets_after_chlo
+      // is deprecated because after that retransmitted CHLO should be buffered
+      // earlier in OnUnauthenticatedPublicHeader().
       bool is_new_connection =
           !buffered_packets_.HasBufferedPackets(current_connection_id_);
       EnqueuePacketResult rs = buffered_packets_.EnqueuePacket(