Throw TypeError when addEventListener or removeEventListener are called without enough arguments

Source/core/events/EventTarget.idl

Index: Source/core/events/EventTarget.idl
diff --git a/Source/core/events/EventTarget.idl b/Source/core/events/EventTarget.idl
index 69a4bc18d7b6e8986ae9c3dbe76371cd5ae3ba73..07365a6900798f62564f00b92fc1dc1f23718553 100644
--- a/Source/core/events/EventTarget.idl
+++ b/Source/core/events/EventTarget.idl
@@ -18,17 +18,24 @@
  * Boston, MA 02110-1301, USA.
  */
 
+// http://dom.spec.whatwg.org/#interface-eventtarget
+
 [
     Custom=ToV8,
+//    TypeChecking=Nullable,
     WillBeGarbageCollected,
 ] interface EventTarget {
-    // FIXME: first 2 args should be required, but throwing TypeError breaks
-    // legacy content.  http://crbug.com/353484
-    void addEventListener([TreatNullAs=NullString] optional DOMString type,
-                          optional EventListener listener,
+    void addEventListener([TreatNullAs=NullString] DOMString type,
+                          // FIXME: should be nullable
+                          EventListener listener,
+                          // FIXME: should be useCapture = false
+                          // http://crbug.com/258153
                           optional boolean useCapture);
-    void removeEventListener([TreatNullAs=NullString] optional DOMString type,
-                             optional EventListener listener,
+    void removeEventListener([TreatNullAs=NullString] DOMString type,
+                             // FIXME: should be nullable
+                             EventListener listener,
+                             // FIXME: should be useCapture = false
+                             // http://crbug.com/258153
                              optional boolean useCapture);
     [RaisesException] boolean dispatchEvent(Event event);
 };