Inherit EventTarget interface instead of duplicating its code

Source/modules/notifications/Notification.idl

Index: Source/modules/notifications/Notification.idl
diff --git a/Source/modules/notifications/Notification.idl b/Source/modules/notifications/Notification.idl
index 0d5d7f700e422e94d67c2c1b1db03dc62dae347d..a8dd30a673384c4780d1af2142a6cc946808784f 100644
--- a/Source/modules/notifications/Notification.idl
+++ b/Source/modules/notifications/Notification.idl
@@ -32,10 +32,9 @@
 [
     Conditional=NOTIFICATIONS|LEGACY_NOTIFICATIONS,
     ActiveDOMObject,
-    EventTarget,
     Constructor(DOMString title, [Default=Undefined] optional Dictionary options),
     ConstructorCallWith=ScriptExecutionContext,
-] interface Notification {
+] interface Notification : EventTarget {
     void show();
     [Conditional=LEGACY_NOTIFICATIONS] void cancel();
     [Conditional=NOTIFICATIONS] void close();
@@ -53,14 +52,5 @@
     [Conditional=LEGACY_NOTIFICATIONS] attribute DOMString dir;
     [Conditional=LEGACY_NOTIFICATIONS] attribute DOMString replaceId;
     [Conditional=NOTIFICATIONS] attribute DOMString tag;
-
-    // EventTarget interface
-    void addEventListener(DOMString type, 
-                          EventListener listener, 
-                          optional boolean useCapture);
-    void removeEventListener(DOMString type, 
-                             EventListener listener, 
-                             optional boolean useCapture);
-    [RaisesException] boolean dispatchEvent(Event evt);
 };