Add path_id to SerializedPacket. No functional change.

net/quic/congestion_control/general_loss_algorithm_test.cc

Index: net/quic/congestion_control/general_loss_algorithm_test.cc
diff --git a/net/quic/congestion_control/general_loss_algorithm_test.cc b/net/quic/congestion_control/general_loss_algorithm_test.cc
index 5e71df1fd4cc8db90fcb47e2396285d93b8c0e91..8cf886f7899bf31fe3822338f9ded97ff3c66881 100644
--- a/net/quic/congestion_control/general_loss_algorithm_test.cc
+++ b/net/quic/congestion_control/general_loss_algorithm_test.cc
@@ -33,9 +33,9 @@ class GeneralLossAlgorithmTest : public ::testing::Test {
 
   void SendDataPacket(QuicPacketNumber packet_number) {
     packets_.push_back(new QuicEncryptedPacket(nullptr, kDefaultLength));
-    SerializedPacket packet(packet_number, PACKET_1BYTE_PACKET_NUMBER,
-                            packets_.back(), 0, new RetransmittableFrames(),
-                            false, false);
+    SerializedPacket packet(kDefaultPathId, packet_number,
+                            PACKET_1BYTE_PACKET_NUMBER, packets_.back(), 0,
+                            new RetransmittableFrames(), false, false);
     unacked_packets_.AddSentPacket(&packet, 0, NOT_RETRANSMISSION, clock_.Now(),
                                    1000, true);
   }