Add original_path_id to SerializedPacket and OnPacketSent. No functional change expected.

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 ea9d79b5903be5ab981c631ecbba58e09befd2a0..d1751ad1a04b123b5aa3cb1f12a41a035df7e5bd 100644
--- a/net/quic/quic_connection.h
+++ b/net/quic/quic_connection.h
@@ -168,6 +168,7 @@ class NET_EXPORT_PRIVATE QuicConnectionDebugVisitor
 
   // Called when a packet has been sent.
   virtual void OnPacketSent(const SerializedPacket& serialized_packet,
+                            QuicPathId original_path_id,
                             QuicPacketNumber original_packet_number,
                             TransmissionType transmission_type,
                             QuicTime sent_time) {}