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

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

Index: chrome/browser/chromeos/login/screens/update_screen.cc
diff --git a/chrome/browser/chromeos/login/screens/update_screen.cc b/chrome/browser/chromeos/login/screens/update_screen.cc
index 40c0cc534286c7729fca064708a2290e815518ce..a1d242e11bd298fd64600531d42fbbd3a6494bab 100644
--- a/chrome/browser/chromeos/login/screens/update_screen.cc
+++ b/chrome/browser/chromeos/login/screens/update_screen.cc
@@ -11,6 +11,7 @@
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/thread_restrictions.h"
+#include "chrome/browser/chromeos/login/error_screens_histogram_helper.h"
 #include "chrome/browser/chromeos/login/screen_manager.h"
 #include "chrome/browser/chromeos/login/screens/error_screen.h"
 #include "chrome/browser/chromeos/login/screens/screen_observer.h"
@@ -91,9 +92,8 @@ UpdateScreen* UpdateScreen::Get(ScreenManager* manager) {
       manager->GetScreen(WizardController::kUpdateScreenName));
 }
 
-UpdateScreen::UpdateScreen(
-    ScreenObserver* screen_observer,
-    UpdateScreenActor* actor)
+UpdateScreen::UpdateScreen(ScreenObserver* screen_observer,
+                           UpdateScreenActor* actor)
     : WizardScreen(screen_observer),
       state_(STATE_IDLE),
       reboot_check_delay_(0),
@@ -105,6 +105,7 @@ UpdateScreen::UpdateScreen(
       actor_(actor),
       is_first_detection_notification_(true),
       is_first_portal_notification_(true),
+      histogram_helper_(new ErrorScreensHistogramHelper("Update")),
       weak_factory_(this) {
   DCHECK(actor_);
   if (actor_)
@@ -297,6 +298,7 @@ void UpdateScreen::CancelUpdate() {
 
 void UpdateScreen::Show() {
   is_shown_ = true;
+  histogram_helper_->OnScreenShow();
   if (actor_) {
     actor_->Show();
     actor_->SetProgress(kBeforeUpdateCheckProgress);
@@ -488,11 +490,13 @@ void UpdateScreen::ShowErrorMessage() {
   state_ = STATE_ERROR;
   GetErrorScreen()->SetUIState(ErrorScreen::UI_STATE_UPDATE);
   get_screen_observer()->ShowErrorScreen();
+  histogram_helper_->OnErrorShow(GetErrorScreen()->GetErrorState());
 }
 
 void UpdateScreen::HideErrorMessage() {
   LOG(WARNING) << "UpdateScreen::HideErrorMessage()";
   get_screen_observer()->HideErrorScreen(this);
+  histogram_helper_->OnErrorHide();
 }
 
 void UpdateScreen::UpdateErrorMessage(