Improve NetworkStateHandler API

ash/system/chromeos/network/network_state_list_detailed_view.cc

Index: ash/system/chromeos/network/network_state_list_detailed_view.cc
diff --git a/ash/system/chromeos/network/network_state_list_detailed_view.cc b/ash/system/chromeos/network/network_state_list_detailed_view.cc
index b8f7d81baf0dc94701afac0b4599219d483b3b42..b8c680418963cf9ff12b9317bf12505805bd6553 100644
--- a/ash/system/chromeos/network/network_state_list_detailed_view.cc
+++ b/ash/system/chromeos/network/network_state_list_detailed_view.cc
@@ -374,7 +374,7 @@ void NetworkStateListDetailedView::UpdateHeaderButtons() {
   button_mobile_->SetVisible(
       handler->TechnologyAvailable(flimflam::kTypeCellular));
   if (proxy_settings_)
-    proxy_settings_->SetEnabled(handler->ActiveNetwork() != NULL);
+    proxy_settings_->SetEnabled(handler->DefaultNetwork() != NULL);
 }
 
 void NetworkStateListDetailedView::UpdateNetworks(
@@ -626,7 +626,7 @@ views::View* NetworkStateListDetailedView::CreateNetworkInfoView() {
   chromeos::NetworkStateHandler* handler = chromeos::NetworkStateHandler::Get();
 
   std::string ip_address("0.0.0.0");
-  const chromeos::NetworkState* network = handler->ActiveNetwork();
+  const chromeos::NetworkState* network = handler->DefaultNetwork();
   if (network)
     ip_address = network->ip_address();
   std::string ethernet_address =