Remove the OnError method from notification delegates.

chrome/browser/local_discovery/privet_notifications.h

 // 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.
 
 #ifndef CHROME_BROWSER_LOCAL_DISCOVERY_PRIVET_NOTIFICATIONS_H_
 #define CHROME_BROWSER_LOCAL_DISCOVERY_PRIVET_NOTIFICATIONS_H_
 
 #include <map>
 #include <string>
 
@@ skipping 116 matching lines @@
   scoped_refptr<PrivetTrafficDetector> traffic_detector_;
 #endif  // ENABLE_MDNS
 };
 
 class PrivetNotificationDelegate : public NotificationDelegate {
  public:
   explicit PrivetNotificationDelegate(content::BrowserContext* profile);
 
   // NotificationDelegate implementation.
   std::string id() const override;
-  void Error() override;
   void ButtonClick(int button_index) override;
 
  private:
   void OpenTab(const GURL& url);
   void DisableNotifications();
 
   ~PrivetNotificationDelegate() override;
 
   content::BrowserContext* profile_;
 };
 
 }  // namespace local_discovery
 
 #endif  // CHROME_BROWSER_LOCAL_DISCOVERY_PRIVET_NOTIFICATIONS_H_