chromeos: Move some network related UI in ui/chromeos/

ash/system/chromeos/network/tray_network_state_observer.cc

Index: ash/system/chromeos/network/tray_network_state_observer.cc
diff --git a/ash/system/chromeos/network/tray_network_state_observer.cc b/ash/system/chromeos/network/tray_network_state_observer.cc
index b83edcbb693293378c43af715526683d68b4fa37..4239be295bbdc7a8d52beb56e91caa4608058cfe 100644
--- a/ash/system/chromeos/network/tray_network_state_observer.cc
+++ b/ash/system/chromeos/network/tray_network_state_observer.cc
@@ -7,11 +7,11 @@
 #include <set>
 #include <string>
 
-#include "ash/system/chromeos/network/network_icon.h"
 #include "base/location.h"
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
+#include "ui/chromeos/network/network_icon.h"
 
 using chromeos::NetworkHandler;
 
@@ -34,7 +34,7 @@ TrayNetworkStateObserver::~TrayNetworkStateObserver() {
 
 void TrayNetworkStateObserver::NetworkListChanged() {
   delegate_->NetworkStateChanged(true);
-  network_icon::PurgeNetworkIconCache();
+  ui::network_icon::PurgeNetworkIconCache();
 }
 
 void TrayNetworkStateObserver::DeviceListChanged() {