Remove the OnError method from notification delegates.

chrome/browser/chromeos/net/network_portal_notification_controller.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/net/network_portal_notification_controller.h"
 
 #include "ash/shell.h"
 #include "ash/system/system_notifier.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "base/basictypes.h"
@@ skipping 37 matching lines @@
       NetworkPortalNotificationController::kNotificationId, false);
 }
 
 class NetworkPortalNotificationControllerDelegate
     : public message_center::NotificationDelegate {
  public:
   NetworkPortalNotificationControllerDelegate(): clicked_(false) {}
 
   // Overridden from message_center::NotificationDelegate:
   virtual void Display() override;
-  virtual void Error() override;
   virtual void Close(bool by_user) override;
   virtual void Click() override;
 
  private:
   virtual ~NetworkPortalNotificationControllerDelegate() {}
 
   bool clicked_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkPortalNotificationControllerDelegate);
 };
 
 void NetworkPortalNotificationControllerDelegate::Display() {
   UMA_HISTOGRAM_ENUMERATION(
       NetworkPortalNotificationController::kNotificationMetric,
       NetworkPortalNotificationController::NOTIFICATION_METRIC_DISPLAYED,
       NetworkPortalNotificationController::NOTIFICATION_METRIC_COUNT);
 }
 
-void NetworkPortalNotificationControllerDelegate::Error() {
-  UMA_HISTOGRAM_ENUMERATION(
-      NetworkPortalNotificationController::kNotificationMetric,
-      NetworkPortalNotificationController::NOTIFICATION_METRIC_ERROR,
-      NetworkPortalNotificationController::NOTIFICATION_METRIC_COUNT);
-}
-
 void NetworkPortalNotificationControllerDelegate::Close(bool by_user) {
   if (clicked_)
     return;
   NetworkPortalNotificationController::UserActionMetric metric =
       by_user
       ? NetworkPortalNotificationController::USER_ACTION_METRIC_CLOSED
       : NetworkPortalNotificationController::USER_ACTION_METRIC_IGNORED;
   UMA_HISTOGRAM_ENUMERATION(
       NetworkPortalNotificationController::kUserActionMetric,
       metric,
@@ skipping 81 matching lines @@
   if (ash::Shell::HasInstance()) {
     ash::Shell::GetInstance()
         ->system_tray_notifier()
         ->NotifyOnCaptivePortalDetected(network->path());
   }
 
   message_center::MessageCenter::Get()->AddNotification(notification.Pass());
 }
 
 }  // namespace chromeos