Land Recent QUIC Changes.

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 2f8c845a7be18dd02ce2be8a201bff626a37ba60..76fe0a7f52a66d70dc23e983dce753bfa7b92fb2 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -1603,10 +1603,16 @@ void QuicConnection::OnRetransmissionTimeout() {
   }
 
   sent_packet_manager_.OnRetransmissionTimeout();
-
   WriteIfNotBlocked();
+  // In the TLP case, the SentPacketManager gives the connection the opportunity
+  // to send new data before retransmitting.
+  if (sent_packet_manager_.MaybeRetransmitTailLossProbe()) {
+    // Send the pending retransmission now that it's been queued.
+    WriteIfNotBlocked();
+  }
 
-  // Ensure the retransmission alarm is always set if there are unacked packets.
+  // Ensure the retransmission alarm is always set if there are unacked packets
+  // and nothing waiting to be sent.
   if (!HasQueuedData() && !retransmission_alarm_->IsSet()) {
     QuicTime rto_timeout = sent_packet_manager_.GetRetransmissionTime();
     if (rto_timeout != QuicTime::Zero()) {