Migrates QUIC sessions to a new network when old network is (about to be) disconnected.

net/quic/quic_utils.cc

Index: net/quic/quic_utils.cc
diff --git a/net/quic/quic_utils.cc b/net/quic/quic_utils.cc
index 6748d6aa1eaeac96f3a3cecda70ab26d85295923..660e10a0a9ba9877025b427bc8dc911719c187a1 100644
--- a/net/quic/quic_utils.cc
+++ b/net/quic/quic_utils.cc
@@ -230,6 +230,10 @@ const char* QuicUtils::ErrorToString(QuicErrorCode error) {
     RETURN_STRING_LITERAL(QUIC_TIMEOUTS_WITH_OPEN_STREAMS);
     RETURN_STRING_LITERAL(QUIC_FAILED_TO_SERIALIZE_PACKET);
     RETURN_STRING_LITERAL(QUIC_TOO_MANY_AVAILABLE_STREAMS);
+    RETURN_STRING_LITERAL(QUIC_IP_ADDRESS_CHANGED);
+    RETURN_STRING_LITERAL(QUIC_CONNECTION_MIGRATION_NO_MIGRATABLE_STREAMS);
+    RETURN_STRING_LITERAL(QUIC_CONNECTION_MIGRATION_TOO_MANY_CHANGES);
+    RETURN_STRING_LITERAL(QUIC_CONNECTION_MIGRATION_NO_NEW_NETWORK);
     RETURN_STRING_LITERAL(QUIC_LAST_ERROR);
     // Intentionally have no default case, so we'll break the build
     // if we add errors and don't put them here.