--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -2327,25 +2327,16 @@ nsGlobalWindowInner::GetScreen(ErrorResu
       aError.Throw(NS_ERROR_UNEXPECTED);
       return nullptr;
     }
   }
 
   return mScreen;
 }
 
-nsIDOMScreen*
-nsGlobalWindowInner::GetScreen()
-{
-  ErrorResult dummy;
-  nsIDOMScreen* screen = GetScreen(dummy);
-  dummy.SuppressException();
-  return screen;
-}
-
 nsHistory*
 nsGlobalWindowInner::GetHistory(ErrorResult& aError)
 {
   if (!mHistory) {
     mHistory = new nsHistory(this);
   }
 
   return mHistory;

--- a/dom/base/nsGlobalWindowInner.h
+++ b/dom/base/nsGlobalWindowInner.h
@@ -774,17 +774,16 @@ public:
   already_AddRefed<nsICSSDeclaration>
     GetComputedStyle(mozilla::dom::Element& aElt, const nsAString& aPseudoElt,
                      mozilla::ErrorResult& aError) override;
   already_AddRefed<mozilla::dom::MediaQueryList> MatchMedia(
     const nsAString& aQuery,
     mozilla::dom::CallerType aCallerType,
     mozilla::ErrorResult& aError);
   nsScreen* GetScreen(mozilla::ErrorResult& aError);
-  nsIDOMScreen* GetScreen() override;
   void MoveTo(int32_t aXPos, int32_t aYPos,
               mozilla::dom::CallerType aCallerType,
               mozilla::ErrorResult& aError);
   void MoveBy(int32_t aXDif, int32_t aYDif,
               mozilla::dom::CallerType aCallerType,
               mozilla::ErrorResult& aError);
   void ResizeTo(int32_t aWidth, int32_t aHeight,
                 mozilla::dom::CallerType aCallerType,

--- a/dom/base/nsGlobalWindowOuter.cpp
+++ b/dom/base/nsGlobalWindowOuter.cpp
@@ -2591,20 +2591,20 @@ nsPIDOMWindowOuter::SetFrameElementInter
 }
 
 Navigator*
 nsGlobalWindowOuter::GetNavigator()
 {
   FORWARD_TO_INNER(Navigator, (), nullptr);
 }
 
-nsIDOMScreen*
+nsScreen*
 nsGlobalWindowOuter::GetScreen()
 {
-  FORWARD_TO_INNER(GetScreen, (), nullptr);
+  FORWARD_TO_INNER(GetScreen, (IgnoreErrors()), nullptr);
 }
 
 void
 nsPIDOMWindowOuter::MaybeActiveMediaComponents()
 {
   if (mMediaSuspend != nsISuspendedTypes::SUSPENDED_BLOCK) {
     return;
   }
@@ -3703,48 +3703,47 @@ nsGlobalWindowOuter::CheckSecurityLeftAn
 #endif
 
     if (nsGlobalWindowOuter* rootWindow = nsGlobalWindowOuter::Cast(GetPrivateRoot())) {
       rootWindow->FlushPendingNotifications(FlushType::Layout);
     }
 
     nsCOMPtr<nsIBaseWindow> treeOwner = GetTreeOwnerWindow();
 
-    nsCOMPtr<nsIDOMScreen> screen = GetScreen();
+    RefPtr<nsScreen> screen = GetScreen();
 
     if (treeOwner && screen) {
-      int32_t screenLeft, screenTop, screenWidth, screenHeight;
       int32_t winLeft, winTop, winWidth, winHeight;
 
       // Get the window size
       treeOwner->GetPositionAndSize(&winLeft, &winTop, &winWidth, &winHeight);
 
       // convert those values to CSS pixels
       // XXX four separate retrievals of the prescontext
       winLeft   = DevToCSSIntPixels(winLeft);
       winTop    = DevToCSSIntPixels(winTop);
       winWidth  = DevToCSSIntPixels(winWidth);
       winHeight = DevToCSSIntPixels(winHeight);
 
       // Get the screen dimensions
       // XXX This should use nsIScreenManager once it's fully fleshed out.
-      screen->GetAvailLeft(&screenLeft);
-      screen->GetAvailWidth(&screenWidth);
-      screen->GetAvailHeight(&screenHeight);
+      int32_t screenLeft = screen->GetAvailLeft(IgnoreErrors());
+      int32_t screenWidth = screen->GetAvailWidth(IgnoreErrors());
+      int32_t screenHeight = screen->GetAvailHeight(IgnoreErrors());
 #if defined(XP_MACOSX)
       /* The mac's coordinate system is different from the assumed Windows'
          system. It offsets by the height of the menubar so that a window
          placed at (0,0) will be entirely visible. Unfortunately that
          correction is made elsewhere (in Widget) and the meaning of
          the Avail... coordinates is overloaded. Here we allow a window
          to be placed at (0,0) because it does make sense to do so.
       */
-      screen->GetTop(&screenTop);
+      int32_t screenTop = screen->GetTop(IgnoreErrors());
 #else
-      screen->GetAvailTop(&screenTop);
+      int32_t screenTop = screen->GetAvailTop(IgnoreErrors());
 #endif
 
       if (aLeft) {
         if (screenLeft+screenWidth < *aLeft+winWidth)
           *aLeft = screenLeft+screenWidth - winWidth;
         if (screenLeft > *aLeft)
           *aLeft = screenLeft;
       }

--- a/dom/base/nsGlobalWindowOuter.h
+++ b/dom/base/nsGlobalWindowOuter.h
@@ -631,17 +631,17 @@ public:
                    nsIPrincipal& aSubjectPrincipal,
                    mozilla::ErrorResult& aError);
   void PrintOuter(mozilla::ErrorResult& aError);
   mozilla::dom::Selection* GetSelectionOuter();
   already_AddRefed<nsISelection> GetSelection() override;
   already_AddRefed<mozilla::dom::MediaQueryList> MatchMediaOuter(
     const nsAString& aQuery,
     mozilla::dom::CallerType aCallerType);
-  nsIDOMScreen* GetScreen() override;
+  nsScreen* GetScreen();
   void MoveToOuter(int32_t aXPos, int32_t aYPos,
                    mozilla::dom::CallerType aCallerType,
                    mozilla::ErrorResult& aError);
   void MoveByOuter(int32_t aXDif, int32_t aYDif,
                    mozilla::dom::CallerType aCallerType,
                    mozilla::ErrorResult& aError);
   nsresult MoveBy(int32_t aXDif, int32_t aYDif) override;
   void ResizeToOuter(int32_t aWidth, int32_t aHeight,

--- a/dom/base/nsPIDOMWindow.h
+++ b/dom/base/nsPIDOMWindow.h
@@ -585,17 +585,16 @@ public:
     mMarkedCCGeneration = aGeneration;
   }
 
   uint32_t GetMarkedCCGeneration()
   {
     return mMarkedCCGeneration;
   }
 
-  virtual nsIDOMScreen* GetScreen() = 0;
   mozilla::dom::Navigator* Navigator();
   virtual mozilla::dom::Location* GetLocation() = 0;
 
   virtual nsresult GetControllers(nsIControllers** aControllers) = 0;
 
   virtual already_AddRefed<nsIDOMWindowCollection> GetFrames() = 0;
 
   virtual nsresult GetInnerWidth(int32_t* aWidth) = 0;
@@ -1089,17 +1088,16 @@ public:
 
   uint32_t GetMarkedCCGeneration()
   {
     return mMarkedCCGeneration;
   }
 
   // XXX(nika): These feel like they should be inner window only, but they're
   // called on the outer window.
-  virtual nsIDOMScreen* GetScreen() = 0;
   virtual mozilla::dom::Navigator* GetNavigator() = 0;
   virtual mozilla::dom::Location* GetLocation() = 0;
 
   virtual nsresult GetPrompter(nsIPrompt** aPrompt) = 0;
   virtual nsresult GetControllers(nsIControllers** aControllers) = 0;
   virtual already_AddRefed<nsISelection> GetSelection() = 0;
   virtual already_AddRefed<nsPIDOMWindowOuter> GetOpener() = 0;
 

--- a/dom/base/nsScreen.cpp
+++ b/dom/base/nsScreen.cpp
@@ -45,17 +45,16 @@ nsScreen::nsScreen(nsPIDOMWindowInner* a
 
 nsScreen::~nsScreen()
 {
 }
 
 
 // QueryInterface implementation for nsScreen
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsScreen)
-  NS_INTERFACE_MAP_ENTRY(nsIDOMScreen)
 NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
 
 NS_IMPL_ADDREF_INHERITED(nsScreen, DOMEventTargetHelper)
 NS_IMPL_RELEASE_INHERITED(nsScreen, DOMEventTargetHelper)
 
 NS_IMPL_CYCLE_COLLECTION_INHERITED(nsScreen,
                                    DOMEventTargetHelper,
                                    mScreenOrientation)
@@ -75,32 +74,16 @@ nsScreen::GetPixelDepth(ErrorResult& aRv
     return -1;
   }
 
   uint32_t depth;
   context->GetDepth(depth);
   return depth;
 }
 
-#define FORWARD_LONG_GETTER(_name)                                              \
-  NS_IMETHODIMP                                                                 \
-  nsScreen::Get ## _name(int32_t* aOut)                                         \
-  {                                                                             \
-    ErrorResult rv;                                                             \
-    *aOut = Get ## _name(rv);                                                   \
-    return rv.StealNSResult();                                                  \
-  }
-
-FORWARD_LONG_GETTER(AvailWidth)
-FORWARD_LONG_GETTER(AvailHeight)
-
-FORWARD_LONG_GETTER(Top)
-FORWARD_LONG_GETTER(AvailTop)
-FORWARD_LONG_GETTER(AvailLeft)
-
 nsPIDOMWindowOuter*
 nsScreen::GetOuter() const
 {
   if (nsPIDOMWindowInner* inner = GetOwner()) {
     return inner->GetOuterWindow();
   }
 
   return nullptr;

--- a/dom/base/nsScreen.h
+++ b/dom/base/nsScreen.h
@@ -5,32 +5,29 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef nsScreen_h___
 #define nsScreen_h___
 
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/ScreenOrientation.h"
 #include "mozilla/DOMEventTargetHelper.h"
 #include "mozilla/ErrorResult.h"
-#include "nsIDOMScreen.h"
 #include "nsCOMPtr.h"
 #include "nsRect.h"
 
 class nsDeviceContext;
 
 // Script "screen" object
 class nsScreen : public mozilla::DOMEventTargetHelper
-               , public nsIDOMScreen
 {
   typedef mozilla::ErrorResult ErrorResult;
 public:
   static already_AddRefed<nsScreen> Create(nsPIDOMWindowInner* aWindow);
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_NSIDOMSCREEN
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsScreen, mozilla::DOMEventTargetHelper)
   NS_REALLY_FORWARD_NSIDOMEVENTTARGET(mozilla::DOMEventTargetHelper)
 
   nsPIDOMWindowInner* GetParentObject() const
   {
     return GetOwner();
   }
 

--- a/dom/interfaces/base/domstubs.idl
+++ b/dom/interfaces/base/domstubs.idl
@@ -29,17 +29,16 @@ namespace dom {
 class DOMException;
 }
 }
 %}
 
 // Base
 interface nsIDOMWindow;
 interface nsIDOMWindowCollection;
-interface nsIDOMScreen;
 
 // Events
 interface nsIDOMEvent;
 interface nsIDOMEventTarget;
 interface nsIDOMEventListener;
 
 // HTML
 interface nsIDOMHTMLHeadElement;

--- a/dom/interfaces/base/moz.build
+++ b/dom/interfaces/base/moz.build
@@ -12,17 +12,16 @@ XPIDL_SOURCES += [
     'nsIBrowser.idl',
     'nsIBrowserDOMWindow.idl',
     'nsIContentPermissionPrompt.idl',
     'nsIContentPrefService2.idl',
     'nsIContentProcess.idl',
     'nsIContentURIGrouper.idl',
     'nsIDOMChromeWindow.idl',
     'nsIDOMGlobalPropertyInitializer.idl',
-    'nsIDOMScreen.idl',
     'nsIDOMWindow.idl',
     'nsIDOMWindowCollection.idl',
     'nsIDOMWindowUtils.idl',
     'nsIFocusManager.idl',
     'nsIIdleObserver.idl',
     'nsIQueryContentEventResult.idl',
     'nsIRemoteBrowser.idl',
     'nsIServiceWorkerManager.idl',

deleted file mode 100644
--- a/dom/interfaces/base/nsIDOMScreen.idl
+++ /dev/null
@@ -1,16 +0,0 @@
-/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "nsIDOMEventTarget.idl"
-
-[builtinclass, uuid(82c7924b-4b46-4e5a-a8d2-6edb5fc0a60d)]
-interface nsIDOMScreen : nsIDOMEventTarget
-{
-  readonly attribute long             top;
-  readonly attribute long             availWidth;
-  readonly attribute long             availHeight;
-  readonly attribute long             availLeft;
-  readonly attribute long             availTop;
-};

--- a/layout/xul/nsMenuPopupFrame.cpp
+++ b/layout/xul/nsMenuPopupFrame.cpp
@@ -14,17 +14,16 @@
 #include "nsNameSpaceManager.h"
 #include "nsViewManager.h"
 #include "nsWidgetsCID.h"
 #include "nsMenuFrame.h"
 #include "nsMenuBarFrame.h"
 #include "nsPopupSetFrame.h"
 #include "nsPIDOMWindow.h"
 #include "nsIDOMEvent.h"
-#include "nsIDOMScreen.h"
 #include "nsIDOMXULMenuListElement.h"
 #include "nsIPresShell.h"
 #include "nsFrameManager.h"
 #include "nsIDocument.h"
 #include "nsRect.h"
 #include "nsIComponentManager.h"
 #include "nsBoxLayoutState.h"
 #include "nsIScrollableFrame.h"

--- a/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
+++ b/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
@@ -20,17 +20,16 @@
 #include "nsIDOMEventTarget.h"
 #include "nsIDOMGeoPositionError.h"
 #include "nsIDOMHTMLInputElement.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeList.h"
 #include "nsIDOMOfflineResourceList.h"
 #include "nsIDOMParser.h"
 #include "nsIDOMRange.h"
-#include "nsIDOMScreen.h"
 #include "nsIDOMSerializer.h"
 #include "nsIDOMXMLDocument.h"
 #include "nsIDOMXULElement.h"
 #include "nsIListBoxObject.h"
 #include "nsIMessageManager.h"
 #include "nsISelection.h"
 #include "nsITreeBoxObject.h"
 #include "nsIWebBrowserPersistable.h"
@@ -64,17 +63,16 @@
 #include "mozilla/dom/NodeBinding.h"
 #include "mozilla/dom/EventBinding.h"
 #include "mozilla/dom/OfflineResourceListBinding.h"
 #include "mozilla/dom/PositionErrorBinding.h"
 #include "mozilla/dom/RangeBinding.h"
 #ifdef MOZ_WEBRTC
 #include "mozilla/dom/RTCDataChannelBinding.h"
 #endif
-#include "mozilla/dom/ScreenBinding.h"
 #include "mozilla/dom/SelectionBinding.h"
 #include "mozilla/dom/StorageEventBinding.h"
 #include "mozilla/dom/StyleSheetBinding.h"
 #include "mozilla/dom/StyleSheetListBinding.h"
 #include "mozilla/dom/SVGElementBinding.h"
 #include "mozilla/dom/TimeEventBinding.h"
 #include "mozilla/dom/TreeBoxObjectBinding.h"
 #include "mozilla/dom/XMLDocumentBinding.h"
@@ -153,17 +151,16 @@ const ComponentsInterfaceShimEntry kComp
   DEFINE_SHIM(NodeList),
   DEFINE_SHIM(Node),
   DEFINE_SHIM(OfflineResourceList),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIDOMParser, DOMParser),
   DEFINE_SHIM(Range),
 #ifdef MOZ_WEBRTC
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIDOMDataChannel, RTCDataChannel),
 #endif
-  DEFINE_SHIM(Screen),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIDOMSerializer, XMLSerializer),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsITreeBoxObject, TreeBoxObject),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIWebBrowserPersistable, FrameLoader),
   DEFINE_SHIM(XMLDocument),
   DEFINE_SHIM(XULElement),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsISelection, Selection),
 };
 

--- a/xpfe/appshell/nsXULWindow.cpp
+++ b/xpfe/appshell/nsXULWindow.cpp
@@ -15,26 +15,27 @@
 #include "nsString.h"
 #include "nsWidgetsCID.h"
 #include "nsThreadUtils.h"
 #include "nsNetCID.h"
 #include "nsQueryObject.h"
 #include "mozilla/Sprintf.h"
 
 //Interfaces needed to be included
+#include "nsGlobalWindowOuter.h"
 #include "nsIAppShell.h"
 #include "nsIAppShellService.h"
 #include "nsIServiceManager.h"
 #include "nsIContentViewer.h"
 #include "nsIDocument.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMElement.h"
 #include "nsIDOMXULElement.h"
 #include "nsPIDOMWindow.h"
-#include "nsIDOMScreen.h"
+#include "nsScreen.h"
 #include "nsIEmbeddingSiteWindow.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsIIOService.h"
 #include "nsILoadContext.h"
 #include "nsIObserverService.h"
 #include "nsIWindowMediator.h"
 #include "nsIScreenManager.h"
@@ -1023,33 +1024,35 @@ NS_IMETHODIMP nsXULWindow::EnsureAuthPro
     if (wwatch)
       wwatch->GetNewAuthPrompter(ourWindow, getter_AddRefs(mAuthPrompter));
   }
   return mAuthPrompter ? NS_OK : NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP nsXULWindow::GetAvailScreenSize(int32_t* aAvailWidth, int32_t* aAvailHeight)
 {
-  nsresult rv;
-
   nsCOMPtr<mozIDOMWindowProxy> domWindow;
   GetWindowDOMWindow(getter_AddRefs(domWindow));
   NS_ENSURE_STATE(domWindow);
 
-  auto* window = nsPIDOMWindowOuter::From(domWindow);
-  NS_ENSURE_STATE(window);
+  auto* window = nsGlobalWindowOuter::Cast(domWindow);
 
-  nsCOMPtr<nsIDOMScreen> screen = window->GetScreen();
+  RefPtr<nsScreen> screen = window->GetScreen();
   NS_ENSURE_STATE(screen);
 
-  rv = screen->GetAvailWidth(aAvailWidth);
-  NS_ENSURE_SUCCESS(rv, rv);
+  ErrorResult rv;
+  *aAvailWidth = screen->GetAvailWidth(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    return rv.StealNSResult();
+  }
 
-  rv = screen->GetAvailHeight(aAvailHeight);
-  NS_ENSURE_SUCCESS(rv, rv);
+  *aAvailHeight = screen->GetAvailHeight(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    return rv.StealNSResult();
+  }
 
   return NS_OK;
 }
 
 // Rounds window size to 1000x1000, or, if there isn't enough available
 // screen space, to a multiple of 200x100.
 NS_IMETHODIMP nsXULWindow::ForceRoundedDimensions()
 {