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

net/quic/quic_connection.cc

Index: net/quic/quic_connection.cc
diff --git a/net/quic/quic_connection.cc b/net/quic/quic_connection.cc
index a3298bcc70abe1439d99a88dc9061cc66e090f64..d94f429c4f0e9569d53fda53292ac2b2babb38b0 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -152,7 +152,7 @@ class PingAlarm : public QuicAlarm::Delegate {
   explicit PingAlarm(QuicConnection* connection) : connection_(connection) {}
 
   QuicTime OnAlarm() override {
-    connection_->SendPing();
+    connection_->SendPing(false);
     return QuicTime::Zero();
   }
 
@@ -1822,8 +1822,8 @@ PeerAddressChangeType QuicConnection::DeterminePeerAddressChangeType() {
   return UNKNOWN;
 }
 
-void QuicConnection::SendPing() {
-  if (retransmission_alarm_->IsSet()) {
+void QuicConnection::SendPing(bool force) {
+  if (!force && retransmission_alarm_->IsSet()) {
     return;
   }
   packet_generator_.AddControlFrame(QuicFrame(QuicPingFrame()));