Log operator code histogram on new metric log

net/base/network_change_notifier.h

Index: net/base/network_change_notifier.h
diff --git a/net/base/network_change_notifier.h b/net/base/network_change_notifier.h
index 044d9f46d211db32664fcad551986a7226fe5a86..68d0afb4320195b5c5aabaeaa4c4deefd2740f85 100644
--- a/net/base/network_change_notifier.h
+++ b/net/base/network_change_notifier.h
@@ -232,6 +232,9 @@ class NET_EXPORT NetworkChangeNotifier {
   // should be called from the network thread to avoid race conditions.
   static void ShutdownHistogramWatcher();
 
+  // Log the |NCN.NetworkOperatorMCCMNC| histogram.
+  static void LogOperatorCodeHistogram(ConnectionType type);
+
   // Allows a second NetworkChangeNotifier to be created for unit testing, so
   // the test suite can create a MockNetworkChangeNotifier, but platform
   // specific NetworkChangeNotifiers can also be created for testing.  To use,