--- a/dom/events/EventStateManager.cpp
+++ b/dom/events/EventStateManager.cpp
@@ -5096,16 +5096,17 @@ EventStateManager::FlushPendingEvents(ns
     shell->FlushPendingNotifications(Flush_InterruptibleLayout);
   }
 }
 
 nsIContent*
 EventStateManager::GetFocusedContent()
 {
   nsIFocusManager* fm = nsFocusManager::GetFocusManager();
+  EnsureDocument(mPresContext);
   if (!fm || !mDocument)
     return nullptr;
 
   nsCOMPtr<nsPIDOMWindowOuter> focusedWindow;
   return nsFocusManager::GetFocusedDescendant(mDocument->GetWindow(), false,
                                               getter_AddRefs(focusedWindow));
 }