UMA: How often are different network error screens encountered during OOBE

chrome/browser/chromeos/login/screens/update_screen.h

Index: chrome/browser/chromeos/login/screens/update_screen.h
diff --git a/chrome/browser/chromeos/login/screens/update_screen.h b/chrome/browser/chromeos/login/screens/update_screen.h
index f828ca03446d8278154eaff7e570cdc420e9e6de..6afcba0b7a1b09e3eb674f47a1f38aeef76b38e8 100644
--- a/chrome/browser/chromeos/login/screens/update_screen.h
+++ b/chrome/browser/chromeos/login/screens/update_screen.h
@@ -21,6 +21,7 @@
 namespace chromeos {
 
 class ErrorScreen;
+class ErrorScreensHistogramHelper;
 class NetworkState;
 class ScreenManager;
 class ScreenObserver;
@@ -164,6 +165,8 @@ class UpdateScreen: public UpdateEngineClient::Observer,
   // the default network.
   bool is_first_portal_notification_;
 
+  scoped_ptr<ErrorScreensHistogramHelper> histogram_helper_;
+
   base::WeakPtrFactory<UpdateScreen> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UpdateScreen);