Remove the OnError method from notification delegates.

chrome/browser/local_discovery/privet_notifications.cc

 // Copyright 2013 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/local_discovery/privet_notifications.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
@@ skipping 355 matching lines @@
 PrivetNotificationDelegate::~PrivetNotificationDelegate() {
 }
 
 std::string PrivetNotificationDelegate::id() const {
   return kPrivetNotificationID;
 }
 
 void PrivetNotificationDelegate::Display() {
 }
 
-void PrivetNotificationDelegate::Error() {
-  LOG(ERROR) << "Error displaying privet notification";
-}
-
 void PrivetNotificationDelegate::Close(bool by_user) {
 }
 
 void PrivetNotificationDelegate::Click() {
 }
 
 void PrivetNotificationDelegate::ButtonClick(int button_index) {
   if (button_index == 0) {
     ReportPrivetUmaEvent(PRIVET_NOTIFICATION_CLICKED);
     OpenTab(GURL(kPrivetNotificationOriginUrl));
@@ skipping 15 matching lines @@
 
 void PrivetNotificationDelegate::DisableNotifications() {
   Profile* profile_obj = Profile::FromBrowserContext(profile_);
 
   profile_obj->GetPrefs()->SetBoolean(
       prefs::kLocalDiscoveryNotificationsEnabled,
       false);
 }
 
 }  // namespace local_discovery