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 11de336664ace13bd992fc0b324db3ce12539b0f..e00b85c9fc883cb7cf925aab1212284219b5a7c4 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 ScreenObserver;
 
@@ -161,6 +162,8 @@ 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);