Introduces ability for session to wait on a migration trigger for a new

net/quic/chromium/mock_network_change_notifier.cc

Index: net/quic/chromium/mock_network_change_notifier.cc
diff --git a/net/quic/chromium/mock_network_change_notifier.cc b/net/quic/chromium/mock_network_change_notifier.cc
index 141e37e0712337d106420f9b04ee7862a3694bc2..e72ba2501cf89c0d16e0712e010680f277653af5 100644
--- a/net/quic/chromium/mock_network_change_notifier.cc
+++ b/net/quic/chromium/mock_network_change_notifier.cc
@@ -63,6 +63,14 @@ void MockNetworkChangeNotifier::QueueNetworkDisconnected(
       NetworkChangeNotifier::DISCONNECTED, network);
 }
 
+void MockNetworkChangeNotifier::NotifyNetworkConnected(
+    NetworkChangeNotifier::NetworkHandle network) {
+  NetworkChangeNotifier::NotifyObserversOfSpecificNetworkChange(
+      NetworkChangeNotifier::CONNECTED, network);
+  // Spin the message loop so the notification is delivered.
+  base::RunLoop().RunUntilIdle();
+}
+
 ScopedMockNetworkChangeNotifier::ScopedMockNetworkChangeNotifier()
     : disable_network_change_notifier_for_tests_(
           new NetworkChangeNotifier::DisableForTest()),