NetworkChangeNotifierChromeos: Handle IPConfig property changes on the default network

chromeos/network/network_state_handler_observer.h

Index: chromeos/network/network_state_handler_observer.h
diff --git a/chromeos/network/network_state_handler_observer.h b/chromeos/network/network_state_handler_observer.h
index a23076cbfa9a810dfd82f1ec5774c68ce3e32b33..d5f134bcc879656fe692b28fd41c71364ef4e1d9 100644
--- a/chromeos/network/network_state_handler_observer.h
+++ b/chromeos/network/network_state_handler_observer.h
@@ -33,8 +33,11 @@ class CHROMEOS_EXPORT NetworkStateHandlerObserver {
   // The list of devices changed, or a property changed (e.g. scanning).
   virtual void DeviceListChanged();
 
-  // The default network changed (includes VPNs) or its connection state
-  // changed. |network| will be NULL if there is no longer a default network.
+  // The default network changed (includes VPNs) or one of its properties
+  // changed. This won't be called if the WiFi signal strength property
+  // changes. If interested in those events, use NetworkPropertiesUpdated()
+  // below.
+  // |network| will be NULL if there is no longer a default network.
   virtual void DefaultNetworkChanged(const NetworkState* network);
 
   // The connection state of |network| changed.