--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -4116,17 +4116,17 @@ ScrollFrameHelper::FireScrollPortEvent()
   }
 
   // If both either overflowed or underflowed then we dispatch only one
   // DOM event.
   bool both = vertChanged && horizChanged &&
                 newVerticalOverflow == newHorizontalOverflow;
   InternalScrollPortEvent::OrientType orient;
   if (both) {
-    orient = InternalScrollPortEvent::both;
+    orient = InternalScrollPortEvent::eBoth;
     mHorizontalOverflow = newHorizontalOverflow;
     mVerticalOverflow = newVerticalOverflow;
   }
   else if (vertChanged) {
     orient = InternalScrollPortEvent::eVertical;
     mVerticalOverflow = newVerticalOverflow;
     if (horizChanged) {
       // We need to dispatch a separate horizontal DOM event. Do that the next

--- a/widget/ContentEvents.h
+++ b/widget/ContentEvents.h
@@ -30,17 +30,17 @@ public:
   {
     return this;
   }
 
   enum OrientType
   {
     eVertical,
     eHorizontal,
-    both       = 2
+    eBoth
   };
 
   InternalScrollPortEvent(bool aIsTrusted, EventMessage aMessage,
                           nsIWidget* aWidget)
     : WidgetGUIEvent(aIsTrusted, aMessage, aWidget, eScrollPortEventClass)
     , orient(eVertical)
   {
   }