[ash-md] Disables proxy settings button when there are no networks

ash/common/system/chromeos/network/network_state_list_detailed_view.h

Index: ash/common/system/chromeos/network/network_state_list_detailed_view.h
diff --git a/ash/common/system/chromeos/network/network_state_list_detailed_view.h b/ash/common/system/chromeos/network/network_state_list_detailed_view.h
index f9e9b08fe79dfc8a32af89f7b2b62cf5eea83571..a3801c37d996b4a6570d66e2b0ebf06c594d31ae 100644
--- a/ash/common/system/chromeos/network/network_state_list_detailed_view.h
+++ b/ash/common/system/chromeos/network/network_state_list_detailed_view.h
@@ -73,8 +73,8 @@ class NetworkStateListDetailedView
   // Update UI components.
   void UpdateTechnologyButton(TrayPopupHeaderButton* button,
                               const chromeos::NetworkTypePattern& technology);
-
   void UpdateNetworkList();
+  void UpdateHeaderButtons();
 
   bool OrderChild(views::View* view, int index);