--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -11776,50 +11776,43 @@ nsIDocument::SetPointerLock(Element* aEl
   esm->SetCursor(aCursorStyle, nullptr, false,
                  0.0f, 0.0f, widget, true);
   EventStateManager::SetPointerLock(widget, aElement);
 
   return true;
 }
 
 void
-nsDocument::UnlockPointer(nsIDocument* aDoc)
+nsIDocument::UnlockPointer(nsIDocument* aDoc)
 {
   if (!EventStateManager::sIsPointerLocked) {
     return;
   }
 
   nsCOMPtr<nsIDocument> pointerLockedDoc =
     do_QueryReferent(EventStateManager::sPointerLockedDoc);
   if (!pointerLockedDoc || (aDoc && aDoc != pointerLockedDoc)) {
     return;
   }
-  nsDocument* doc = static_cast<nsDocument*>(pointerLockedDoc.get());
-  if (!doc->SetPointerLock(nullptr, NS_STYLE_CURSOR_AUTO)) {
+  if (!pointerLockedDoc->SetPointerLock(nullptr, NS_STYLE_CURSOR_AUTO)) {
     return;
   }
 
   nsCOMPtr<Element> pointerLockedElement =
     do_QueryReferent(EventStateManager::sPointerLockedElement);
-  ChangePointerLockedElement(nullptr, doc, pointerLockedElement);
+  ChangePointerLockedElement(nullptr, pointerLockedDoc, pointerLockedElement);
 
   RefPtr<AsyncEventDispatcher> asyncDispatcher =
     new AsyncEventDispatcher(pointerLockedElement,
                              NS_LITERAL_STRING("MozDOMPointerLock:Exited"),
                              true, true);
   asyncDispatcher->RunDOMEventWhenSafe();
 }
 
 void
-nsIDocument::UnlockPointer(nsIDocument* aDoc)
-{
-  nsDocument::UnlockPointer(aDoc);
-}
-
-void
 nsIDocument::UpdateVisibilityState()
 {
   dom::VisibilityState oldState = mVisibilityState;
   mVisibilityState = ComputeVisibilityState();
   if (oldState != mVisibilityState) {
     nsContentUtils::DispatchTrustedEvent(this, static_cast<nsIDocument*>(this),
                                          NS_LITERAL_STRING("visibilitychange"),
                                          /* bubbles = */ true,

--- a/dom/base/nsDocument.h
+++ b/dom/base/nsDocument.h
@@ -313,18 +313,16 @@ public:
   // Returns strong references to mBlockedTrackingNodes. (nsIDocument.h)
   //
   // This array contains nodes that have been blocked to prevent
   // user tracking. They most likely have had their nsIChannel
   // canceled by the URL classifier (Safebrowsing).
   //
   already_AddRefed<nsSimpleContentList> BlockedTrackingNodes() const;
 
-  static void UnlockPointer(nsIDocument* aDoc = nullptr);
-
   virtual void DocAddSizeOfExcludingThis(nsWindowSizes& aWindowSizes) const override;
   // DocAddSizeOfIncludingThis is inherited from nsIDocument.
 
   virtual nsIDOMNode* AsDOMNode() override { return this; }
 
 protected:
   friend class nsNodeUtils;