Allow IP migration.

net/quic/core/quic_protocol.h

Index: net/quic/core/quic_protocol.h
diff --git a/net/quic/core/quic_protocol.h b/net/quic/core/quic_protocol.h
index bb8cc1d61f5372dd30b48c5c35a8969224cb210e..191883280f4d7e786e374e97b2485d125d0ddcf7 100644
--- a/net/quic/core/quic_protocol.h
+++ b/net/quic/core/quic_protocol.h
@@ -1181,14 +1181,14 @@ enum PeerAddressChangeType {
   PORT_CHANGE,
   // IPv4 address changed, but within the /24 subnet (port may have changed.)
   IPV4_SUBNET_CHANGE,
+  // IPv4 address changed, excluding /24 subnet change (port may have changed.)
+  IPV4_TO_IPV4_CHANGE,
   // IP address change from an IPv4 to an IPv6 address (port may have changed.)
   IPV4_TO_IPV6_CHANGE,
   // IP address change from an IPv6 to an IPv4 address (port may have changed.)
   IPV6_TO_IPV4_CHANGE,
   // IP address change from an IPv6 to an IPv6 address (port may have changed.)
   IPV6_TO_IPV6_CHANGE,
-  // All other peer address changes.
-  UNSPECIFIED_CHANGE,
 };
 
 struct NET_EXPORT_PRIVATE QuicFrame {