Template methods on Timer classes instead of the classes themselves.

chrome/browser/notifications/extension_welcome_notification.h

 // 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.
 
 #ifndef CHROME_BROWSER_NOTIFICATIONS_EXTENSION_WELCOME_NOTIFICATION_H_
 #define CHROME_BROWSER_NOTIFICATIONS_EXTENSION_WELCOME_NOTIFICATION_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 134 matching lines @@
 
   // If the preferences are still syncing, store the last notification here
   // so we can replay ShowWelcomeNotificationIfNecessary once the sync finishes.
   // Simplifying Assumption: The delayed notification has passed the
   // extension ID check. This means we do not need to store all of the
   // notifications that may also show a welcome notification.
   scoped_ptr<Notification> delayed_notification_;
 
   // If the welcome notification is shown, this timer tracks when to hide the
   // welcome notification.
-  scoped_ptr<base::OneShotTimer<ExtensionWelcomeNotification> >
-      expiration_timer_;
+  scoped_ptr<base::OneShotTimer> expiration_timer_;
 
   // Delegate for Chrome global calls like base::Time::GetTime() for
   // testability.
   scoped_ptr<Delegate> delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionWelcomeNotification);
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_EXTENSION_WELCOME_NOTIFICATION_H_