Remove the OnError method from notification delegates.

chrome/browser/ui/ash/screenshot_taker.cc

 // Copyright (c) 2012 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/ui/ash/screenshot_taker.h"
 
 #include <climits>
 #include <string>
 
 #include "ash/shell.h"
@@ skipping 110 matching lines @@
   ScreenshotTakerNotificationDelegate(bool success,
                                       Profile* profile,
                                       const base::FilePath& screenshot_path)
       : success_(success),
         profile_(profile),
         screenshot_path_(screenshot_path) {
   }
 
   // Overridden from NotificationDelegate:
   void Display() override {}
-  void Error() override {}
   void Close(bool by_user) override {}
   void Click() override {
     if (!success_)
       return;
 #if defined(OS_CHROMEOS)
     file_manager::util::ShowItemInFolder(profile_, screenshot_path_);
 #else
     // TODO(sschmitz): perhaps add similar action for Windows.
 #endif
   }
@@ skipping 479 matching lines @@
 }
 
 void ScreenshotTaker::SetScreenshotBasenameForTest(
     const std::string& basename) {
   screenshot_basename_for_test_ = basename;
 }
 
 void ScreenshotTaker::SetScreenshotProfileForTest(Profile* profile) {
   profile_for_test_ = profile;
 }