IDL: make optional arguments (without default) explicit sometimes

Source/modules/mediastream/RTCDTMFSender.cpp

 /*
  * 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 71 matching lines @@
 MediaStreamTrack* RTCDTMFSender::track() const
 {
     return m_track.get();
 }
 
 String RTCDTMFSender::toneBuffer() const
 {
     return m_handler->currentToneBuffer();
 }
 
-void RTCDTMFSender::insertDTMF(const String& tones, ExceptionState& exceptionState)
-{
-    insertDTMF(tones, defaultToneDurationMs, defaultInterToneGapMs, exceptionState);
-}
-
-void RTCDTMFSender::insertDTMF(const String& tones, long duration, ExceptionState& exceptionState)
-{
-    insertDTMF(tones, duration, defaultInterToneGapMs, exceptionState);
-}
-
 void RTCDTMFSender::insertDTMF(const String& tones, long duration, long interToneGap, ExceptionState& exceptionState)
 {
     if (!canInsertDTMF()) {
         exceptionState.throwDOMException(NotSupportedError, "The 'canInsertDTMF' attribute is false: this sender cannot send DTMF.");
         return;
     }
 
     if (duration > maxToneDurationMs || duration < minToneDurationMs) {
         exceptionState.throwDOMException(SyntaxError, ExceptionMessages::indexOutsideRange("duration", duration, minToneDurationMs, ExceptionMessages::ExclusiveBound, maxToneDurationMs, ExceptionMessages::ExclusiveBound));
         return;
@@ skipping 54 matching lines @@
 }
 
 void RTCDTMFSender::trace(Visitor* visitor)
 {
     visitor->trace(m_track);
     visitor->trace(m_scheduledEvents);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace blink