IDL: Add [Custom=CallEpilogue] to eliminate CG special cases

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 b7279b3b81ab8dd3fc725b412b11831c66bfc1ed..94c0757ee857db49221f7a2042b166346921858a 100644
--- a/Source/core/events/EventTarget.idl
+++ b/Source/core/events/EventTarget.idl
@@ -30,7 +30,7 @@
     // legacy content.  http://crbug.com/353484
     // FIXME: type should not be nullable.
     // FIXME: capture should have a default value false.
-    void addEventListener(optional DOMString? type, optional EventListener? listener, optional boolean capture);
-    void removeEventListener(optional DOMString? type, optional EventListener? listener, optional boolean capture);
+    [Custom=CallEpilogue] void addEventListener(optional DOMString? type, optional EventListener? listener, optional boolean capture);
+    [Custom=CallEpilogue] void removeEventListener(optional DOMString? type, optional EventListener? listener, optional boolean capture);
     [RaisesException] boolean dispatchEvent(Event event);
 };