Makes NetworkChangeType enum public.

net/base/network_change_notifier.cc

Index: net/base/network_change_notifier.cc
diff --git a/net/base/network_change_notifier.cc b/net/base/network_change_notifier.cc
index 52e5ce34c217ee956e8d455a283a953afc644b7d..2a4b6131f14922b26138124a67790838b413fdb6 100644
--- a/net/base/network_change_notifier.cc
+++ b/net/base/network_change_notifier.cc
@@ -923,6 +923,16 @@ void NetworkChangeNotifier::NotifyObserversOfNetworkChangeForTests(
 }
 
 // static
+void NetworkChangeNotifier::NotifyObserversOfSpecificNetworkChangeForTests(
+    NetworkChangeType type,
+    NetworkHandle network) {
+  if (g_network_change_notifier) {
+    g_network_change_notifier->NotifyObserversOfSpecificNetworkChangeImpl(
+        type, network);
+  }
+}
+
+// static
 void NetworkChangeNotifier::NotifyObserversOfInitialDNSConfigReadForTests() {
   if (g_network_change_notifier)
     g_network_change_notifier->NotifyObserversOfInitialDNSConfigReadImpl();