Explicitly mark first 2 args of addEventListener/removeEventListener as optional

Source/core/events/EventTarget.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 89 matching lines @@
     void ref() { refEventTarget(); }
     void deref() { derefEventTarget(); }
 
     virtual const AtomicString& interfaceName() const = 0;
     virtual ExecutionContext* executionContext() const = 0;
 
     virtual Node* toNode();
     virtual DOMWindow* toDOMWindow();
     virtual MessagePort* toMessagePort();
 
+    // FIXME: first 2 args to addEventListener and removeEventListener should
+    // be required (per spec), but throwing TypeError breaks legacy content.
+    // http://crbug.com/353484
+    bool addEventListener() { return false; }
+    bool addEventListener(const AtomicString& eventType) { return false; }
     virtual bool addEventListener(const AtomicString& eventType, PassRefPtr<EventListener>, bool useCapture = false);
+    bool removeEventListener() { return false; }
+    bool removeEventListener(const AtomicString& eventType) { return false; }
     virtual bool removeEventListener(const AtomicString& eventType, EventListener*, bool useCapture = false);
     virtual void removeAllEventListeners();
     virtual bool dispatchEvent(PassRefPtr<Event>);
     bool dispatchEvent(PassRefPtr<Event>, ExceptionState&); // DOM API
     virtual void uncaughtExceptionInEventHandler();
 
     // Used for legacy "onEvent" attribute APIs.
     bool setAttributeEventListener(const AtomicString& eventType, PassRefPtr<EventListener>);
     EventListener* getAttributeEventListener(const AtomicString& eventType);
 
@@ skipping 114 matching lines @@
     virtual void refEventTarget() OVERRIDE FINAL { ref(); } \
     virtual void derefEventTarget() OVERRIDE FINAL { deref(); } \
     typedef int thisIsHereToForceASemiColonAfterThisEventTargetMacro
 
 // Use this macro if your EventTarget subclass is also a subclass of WTF::RefCounted.
 // A ref-counted class that uses a different method of refcounting should use DEFINE_EVENT_TARGET_REFCOUNTING directly.
 // Both of these macros are meant to be placed just before the "public:" section of the class declaration.
 #define REFCOUNTED_EVENT_TARGET(className) DEFINE_EVENT_TARGET_REFCOUNTING(RefCounted<className>)
 
 #endif // EventTarget_h