relnote: Add MigrateSocket method to quic_test_client. In loadtesting,

net/tools/quic/test_tools/quic_test_client.cc

Index: net/tools/quic/test_tools/quic_test_client.cc
diff --git a/net/tools/quic/test_tools/quic_test_client.cc b/net/tools/quic/test_tools/quic_test_client.cc
index 7e7022e003e71eb4c8a6479230073762881a0b2d..1b01daadc6acf952054bd8afc7eb6566fda62a80 100644
--- a/net/tools/quic/test_tools/quic_test_client.cc
+++ b/net/tools/quic/test_tools/quic_test_client.cc
@@ -584,6 +584,10 @@ void QuicTestClient::Bind(IPEndPoint* local_address) {
   DLOG(WARNING) << "Bind will be done during connect";
 }
 
+void QuicTestClient::MigrateSocket(const IPAddressNumber& new_host) {
+  client_->MigrateSocket(new_host);
+}
+
 string QuicTestClient::SerializeMessage(const HTTPMessage& message) {
   LOG(DFATAL) << "Not implemented";
   return "";