Use weak presshell ptr, since we can. More on bug 230380

content/events/src/nsEventListenerManager.cpp

@@ -1992,7 +1992,7 @@ nsEventListenerManager::FixContextMenuEvent(nsIPresContext* aPresContext,
   nsCOMPtr<nsIDOMEventTarget> currentTarget(aCurrentTarget);
   nsCOMPtr<nsIDOMElement> currentFocus;
   nsCOMPtr<nsIDocument> doc;
-  nsCOMPtr<nsIPresShell> shell = aPresContext->PresShell();
+  nsIPresShell* shell = aPresContext->PresShell();
   nsString empty;
 
   if (aEvent->message == NS_CONTEXTMENU_KEY) {