--- a/dom/events/Event.cpp
+++ b/dom/events/Event.cpp
@@ -653,23 +653,23 @@ PopupAllowedForEvent(const char *eventNa
     startiter = enditer;
   }
 
   return false;
 }
 
 // static
 PopupControlState
-Event::GetEventPopupControlState(WidgetEvent* aEvent, nsIDOMEvent* aDOMEvent)
+Event::GetEventPopupControlState(WidgetEvent* aEvent, Event* aDOMEvent)
 {
   // generally if an event handler is running, new windows are disallowed.
   // check for exceptions:
   PopupControlState abuse = openAbused;
 
-  if (aDOMEvent && aDOMEvent->InternalDOMEvent()->GetWantsPopupControlCheck()) {
+  if (aDOMEvent && aDOMEvent->GetWantsPopupControlCheck()) {
     nsAutoString type;
     aDOMEvent->GetType(type);
     if (PopupAllowedForEvent(NS_ConvertUTF16toUTF8(type).get())) {
       return openAllowed;
     }
   }
 
   switch(aEvent->mClass) {

--- a/dom/events/Event.h
+++ b/dom/events/Event.h
@@ -158,17 +158,17 @@ public:
   NS_DECL_NSIDOMEVENT
 
   void InitPresContextData(nsPresContext* aPresContext);
 
   // Returns true if the event should be trusted.
   bool Init(EventTarget* aGlobal);
 
   static PopupControlState GetEventPopupControlState(WidgetEvent* aEvent,
-                                                     nsIDOMEvent* aDOMEvent = nullptr);
+                                                     Event* aDOMEvent = nullptr);
 
   static void PopupAllowedEventsChanged();
 
   static void Shutdown();
 
   static const char* GetEventName(EventMessage aEventType);
   static CSSIntPoint GetClientCoords(nsPresContext* aPresContext,
                                      WidgetEvent* aEvent,