--- a/dom/events/EventDispatcher.cpp
+++ b/dom/events/EventDispatcher.cpp
@@ -853,23 +853,16 @@ EventDispatcher::CreateEvent(EventTarget
     PageTransitionEventInit init;
     nsRefPtr<PageTransitionEvent> event =
       PageTransitionEvent::Constructor(aOwner, EmptyString(), init);
     event.forget(aDOMEvent);
     return NS_OK;
   }
   if (aEventType.LowerCaseEqualsLiteral("scrollareaevent"))
     return NS_NewDOMScrollAreaEvent(aDOMEvent, aOwner, aPresContext, nullptr);
-  if (aEventType.LowerCaseEqualsLiteral("closeevent")) {
-    CloseEventInit init;
-    nsRefPtr<CloseEvent> event =
-      CloseEvent::Constructor(aOwner, EmptyString(), init);
-    event.forget(aDOMEvent);
-    return NS_OK;
-  }
   // XXXkhuey Chrome supports popstateevent here, even though it provides no
   // initPopStateEvent method.  This is nuts ... but copying it is unlikely to
   // break the web.
   if (aEventType.LowerCaseEqualsLiteral("popstateevent")) {
     AutoJSContext cx;
     RootedDictionary<PopStateEventInit> init(cx);
     nsRefPtr<PopStateEvent> event =
       PopStateEvent::Constructor(aOwner, EmptyString(), init);

--- a/dom/webidl/CloseEvent.webidl
+++ b/dom/webidl/CloseEvent.webidl
@@ -10,25 +10,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/multipage/network.html#closeevent
  */
 
 [Constructor(DOMString type, optional CloseEventInit eventInitDict),LegacyEventInit]
 interface CloseEvent : Event
 {
   readonly attribute boolean wasClean;
   readonly attribute unsigned short code;
-  readonly attribute DOMString? reason;
-
-  [Throws]
-  void initCloseEvent(DOMString aType,
-                      boolean aCanBubble,
-                      boolean aCancelable,
-                      boolean aWasClean,
-                      unsigned short aReasonCode,
-                      DOMString? aReason);
+  readonly attribute DOMString reason;
 };
 
 dictionary CloseEventInit : EventInit
 {
   boolean wasClean = false;
   unsigned short code = 0;
   DOMString reason = "";
 };

deleted file mode 100644
--- a/testing/web-platform/meta/websockets/interfaces/CloseEvent/historical.html.ini
+++ /dev/null
@@ -1,10 +0,0 @@
-[historical.html]
-  type: testharness
-  [createEvent("CloseEvent")]
-    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1161950
-    expected: FAIL
-
-  [initCloseEvent]
-    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1161950
-    expected: FAIL
-