Refactor Timer classes in preparation for landing FrameTimers.

third_party/WebKit/Source/modules/peerconnection/RTCDTMFSender.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 58 matching lines @@
     // ActiveDOMObject
     void stop() override;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     RTCDTMFSender(ExecutionContext*, MediaStreamTrack*, std::unique_ptr<WebRTCDTMFSenderHandler>);
     void dispose();
 
     void scheduleDispatchEvent(Event*);
-    void scheduledEventTimerFired(Timer<RTCDTMFSender>*);
+    void scheduledEventTimerFired(TimerBase*);
 
     // WebRTCDTMFSenderHandlerClient
     void didPlayTone(const WebString&) override;
 
     Member<MediaStreamTrack> m_track;
     int m_duration;
     int m_interToneGap;
 
     std::unique_ptr<WebRTCDTMFSenderHandler> m_handler;
 
     bool m_stopped;
 
     Timer<RTCDTMFSender> m_scheduledEventTimer;
     HeapVector<Member<Event>> m_scheduledEvents;
 };
 
 } // namespace blink
 
 #endif // RTCDTMFSender_h