--- a/dom/events/Event.cpp
+++ b/dom/events/Event.cpp
@@ -782,17 +782,17 @@ Event::GetEventPopupControlState(WidgetE
       case NS_MOUSE_DOUBLECLICK :
         if (PopupAllowedForEvent("dblclick")) {
           abuse = openControlled;
         }
         break;
       }
     }
     break;
-  case NS_FORM_EVENT :
+  case eFormEventClass:
     // For these following events only allow popups if they're
     // triggered while handling user input. See
     // nsPresShell::HandleEventInternal() for details.
     if (EventStateManager::IsHandlingUserInput()) {
       switch(aEvent->message) {
       case NS_FORM_SUBMIT :
         if (PopupAllowedForEvent("submit")) {
           abuse = openControlled;

--- a/widget/BasicEvents.h
+++ b/widget/BasicEvents.h
@@ -49,17 +49,17 @@ enum EventClassID MOZ_ENUM_TYPE(EventCla
   // TouchEvents.h
   eGestureNotifyEventClass,          // WidgetGestureNotifyEvent
   eSimpleGestureEventClass,          // WidgetSimpleGestureEvent
   eTouchEventClass,                  // WidgetTouchEvent
 
   // ContentEvents.h
   eScrollPortEventClass,             // InternalScrollPortEvent
   eScrollAreaEventClass,             // InternalScrollAreaEvent
-  NS_FORM_EVENT,                     // InternalFormEvent
+  eFormEventClass,                   // InternalFormEvent
   NS_FOCUS_EVENT,                    // InternalFocusEvent
   NS_CLIPBOARD_EVENT,                // InternalClipboardEvent
   NS_TRANSITION_EVENT,               // InternalTransitionEvent
   NS_ANIMATION_EVENT,                // InternalAnimationEvent
   NS_SVGZOOM_EVENT,                  // InternalSVGZoomEvent
   NS_SMIL_TIME_EVENT,                // InternalSMILTimeEvent
 
   // MiscEvents.h

--- a/widget/ContentEvents.h
+++ b/widget/ContentEvents.h
@@ -116,25 +116,25 @@ public:
  * originator is a weak pointer (does not hold a strong reference).
  ******************************************************************************/
 
 class InternalFormEvent : public WidgetEvent
 {
 public:
   virtual InternalFormEvent* AsFormEvent() MOZ_OVERRIDE { return this; }
 
-  InternalFormEvent(bool aIsTrusted, uint32_t aMessage) :
-    WidgetEvent(aIsTrusted, aMessage, NS_FORM_EVENT),
-    originator(nullptr)
+  InternalFormEvent(bool aIsTrusted, uint32_t aMessage)
+    : WidgetEvent(aIsTrusted, aMessage, eFormEventClass)
+    , originator(nullptr)
   {
   }
 
   virtual WidgetEvent* Duplicate() const MOZ_OVERRIDE
   {
-    MOZ_ASSERT(mClass == NS_FORM_EVENT,
+    MOZ_ASSERT(mClass == eFormEventClass,
                "Duplicate() must be overridden by sub class");
     InternalFormEvent* result = new InternalFormEvent(false, message);
     result->AssignFormEventData(*this, true);
     result->mFlags = mFlags;
     return result;
   }
 
   nsIContent *originator;