Trigger internal QUIC "trace graph" trace dumping also in cases where

net/quic/quic_connection.h

Index: net/quic/quic_connection.h
diff --git a/net/quic/quic_connection.h b/net/quic/quic_connection.h
index a98458bb0de5ef1d7cb4c97e3e02fb0733a777a9..55bbda1a61ad3289a53fac996733c45a79e4cc48 100644
--- a/net/quic/quic_connection.h
+++ b/net/quic/quic_connection.h
@@ -198,6 +198,9 @@ class NET_EXPORT_PRIVATE QuicConnectionDebugVisitor
   // in the revival of a packet via FEC.
   virtual void OnRevivedPacket(const QuicPacketHeader& revived_header,
                                base::StringPiece payload) {}
+
+  // Called when the connection is closed.
+  virtual void OnConnectionClosed(QuicErrorCode error, bool from_peer) {}
 };
 
 class NET_EXPORT_PRIVATE QuicConnectionHelperInterface {