Provide default implementations for NotificationDelegate methods.

chrome/browser/notifications/notification_test_util.h

 // 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.
 
 #ifndef CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_
 
 #include <set>
 #include <string>
 
 #include "chrome/browser/notifications/notification.h"
 #include "chrome/browser/notifications/notification_object_proxy.h"
 #include "chrome/browser/notifications/notification_ui_manager.h"
 #include "chrome/browser/notifications/sync_notifier/chrome_notifier_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "ui/gfx/size.h"
 
 // NotificationDelegate which does nothing, useful for testing when
 // the notification events are not important.
 class MockNotificationDelegate : public NotificationDelegate {
  public:
   explicit MockNotificationDelegate(const std::string& id);
 
   // NotificationDelegate interface.
-  void Display() override {}
-  void Error() override {}
-  void Close(bool by_user) override {}
-  void Click() override {}
   std::string id() const override;
 
  private:
   ~MockNotificationDelegate() override;
 
   std::string id_;
 
   DISALLOW_COPY_AND_ASSIGN(MockNotificationDelegate);
 };
 
@@ skipping 86 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(StubNotificationUIManager);
   Notification notification_;
   Profile* profile_;
   std::string dismissed_id_;
   GURL welcome_origin_;
   bool welcomed_;
   size_t added_notifications_;
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_