--- a/dom/ipc/TabParent.cpp
+++ b/dom/ipc/TabParent.cpp
@@ -298,20 +298,16 @@ TabParent::AddWindowListeners()
   if (mFrameElement && mFrameElement->OwnerDoc()) {
     if (nsCOMPtr<nsPIDOMWindowOuter> window = mFrameElement->OwnerDoc()->GetWindow()) {
       nsCOMPtr<EventTarget> eventTarget = window->GetTopWindowRoot();
       if (eventTarget) {
         eventTarget->AddEventListener(NS_LITERAL_STRING("MozUpdateWindowPos"),
                                       this, false, false);
       }
     }
-    if (nsIPresShell* shell = mFrameElement->OwnerDoc()->GetShell()) {
-      mPresShellWithRefreshListener = shell;
-      shell->AddPostRefreshObserver(this);
-    }
 
     RefPtr<AudioChannelService> acs = AudioChannelService::GetOrCreate();
     if (acs) {
       acs->RegisterTabParent(this);
     }
   }
 }
 
@@ -321,36 +317,24 @@ TabParent::RemoveWindowListeners()
   if (mFrameElement && mFrameElement->OwnerDoc()->GetWindow()) {
     nsCOMPtr<nsPIDOMWindowOuter> window = mFrameElement->OwnerDoc()->GetWindow();
     nsCOMPtr<EventTarget> eventTarget = window->GetTopWindowRoot();
     if (eventTarget) {
       eventTarget->RemoveEventListener(NS_LITERAL_STRING("MozUpdateWindowPos"),
                                        this, false);
     }
   }
-  if (mPresShellWithRefreshListener) {
-    mPresShellWithRefreshListener->RemovePostRefreshObserver(this);
-    mPresShellWithRefreshListener = nullptr;
-  }
 
   RefPtr<AudioChannelService> acs = AudioChannelService::GetOrCreate();
   if (acs) {
     acs->UnregisterTabParent(this);
   }
 }
 
 void
-TabParent::DidRefresh()
-{
-  if (mChromeOffset != -GetChildProcessOffset()) {
-    UpdatePosition();
-  }
-}
-
-void
 TabParent::GetAppType(nsAString& aOut)
 {
   aOut.Truncate();
   nsCOMPtr<Element> elem = do_QueryInterface(mFrameElement);
   if (!elem) {
     return;
   }
 

--- a/dom/ipc/TabParent.h
+++ b/dom/ipc/TabParent.h
@@ -85,17 +85,16 @@ class StructuredCloneData;
 class TabParent final : public PBrowserParent
                       , public nsIDOMEventListener
                       , public nsITabParent
                       , public nsIAuthPromptProvider
                       , public nsISecureBrowserUI
                       , public nsIKeyEventInPluginCallback
                       , public nsSupportsWeakReference
                       , public TabContext
-                      , public nsAPostRefreshObserver
                       , public nsIWebBrowserPersistable
                       , public LiveResizeListener
 {
   typedef mozilla::dom::ClonedMessageData ClonedMessageData;
 
   virtual ~TabParent();
 
 public:
@@ -153,18 +152,16 @@ public:
   nsIXULBrowserWindow* GetXULBrowserWindow();
 
   void Destroy();
 
   void RemoveWindowListeners();
 
   void AddWindowListeners();
 
-  void DidRefresh() override;
-
   virtual mozilla::ipc::IPCResult RecvMoveFocus(const bool& aForward,
                                                 const bool& aForDocumentNavigation) override;
 
   virtual mozilla::ipc::IPCResult RecvSizeShellTo(const uint32_t& aFlags,
                                                   const int32_t& aWidth,
                                                   const int32_t& aHeight,
                                                   const int32_t& aShellItemWidth,
                                                   const int32_t& aShellItemHeight) override;
@@ -745,18 +742,16 @@ private:
   nsCursor mCursor;
   nsCOMPtr<imgIContainer> mCustomCursor;
   uint32_t mCustomCursorHotspotX, mCustomCursorHotspotY;
 
   // True if the cursor changes from the TabChild should change the widget
   // cursor.  This happens whenever the cursor is in the tab's region.
   bool mTabSetsCursor;
 
-  RefPtr<nsIPresShell> mPresShellWithRefreshListener;
-
   bool mHasContentOpener;
 
 #ifdef DEBUG
   int32_t mActiveSupressDisplayportCount;
 #endif
 
   ShowInfo GetShowInfo();