Use NetworkConnectionObserver to trigger connect failure notifications

ui/chromeos/network/network_state_notifier.h

Index: ui/chromeos/network/network_state_notifier.h
diff --git a/ui/chromeos/network/network_state_notifier.h b/ui/chromeos/network/network_state_notifier.h
index 028391f438633766d096e98d68ebad96dfc78a10..25b65fd355d672011590330aa35590502a6fbd40 100644
--- a/ui/chromeos/network/network_state_notifier.h
+++ b/ui/chromeos/network/network_state_notifier.h
@@ -12,6 +12,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
+#include "chromeos/network/network_connection_observer.h"
 #include "chromeos/network/network_state_handler_observer.h"
 #include "ui/chromeos/ui_chromeos_export.h"
 
@@ -35,16 +36,19 @@ class NetworkConnect;
 // 2. It observes NetworkState changes to generate notifications when a
 //    Cellular network is out of credits.
 class UI_CHROMEOS_EXPORT NetworkStateNotifier :
+      public chromeos::NetworkConnectionObserver,
       public chromeos::NetworkStateHandlerObserver {
  public:
   explicit NetworkStateNotifier(NetworkConnect* network_connect);
-  virtual ~NetworkStateNotifier();
+  ~NetworkStateNotifier() override;
+
+  // NetworkConnectionObserver
+  void ConnectFailed(const std::string& service_path,
+                     const std::string& error_name) override;
 
   // NetworkStateHandlerObserver
-  virtual void DefaultNetworkChanged(
-      const chromeos::NetworkState* network) override;
-  virtual void NetworkPropertiesUpdated(
-      const chromeos::NetworkState* network) override;
+  void DefaultNetworkChanged(const chromeos::NetworkState* network) override;
+  void NetworkPropertiesUpdated(const chromeos::NetworkState* network) override;
 
   // Show a connection error notification. If |error_name| matches an error
   // defined in NetworkConnectionHandler for connect, configure, or activation