--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -79,17 +79,16 @@
 #include "nsICookieService.h"
 #include "nsIDocShellTreeItem.h"
 #include "nsIDocShellTreeOwner.h"
 #include "nsIDocument.h"
 #include "nsIDocumentLoaderFactory.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMStorage.h"
-#include "nsIDOMWindow.h"
 #include "nsIEditingSession.h"
 #include "nsIExternalProtocolService.h"
 #include "nsIFormPOSTActionChannel.h"
 #include "nsIFrame.h"
 #include "nsIGlobalHistory2.h"
 #include "nsIGlobalObject.h"
 #include "nsIHttpChannel.h"
 #include "nsIHttpChannelInternal.h"
@@ -542,18 +541,17 @@ nsDocShell::GetInterface(const nsIID& aI
 
   if (aIID.Equals(NS_GET_IID(nsICommandManager))) {
     NS_ENSURE_SUCCESS(EnsureCommandHandler(), NS_ERROR_FAILURE);
     *aSink = mCommandManager;
   } else if (aIID.Equals(NS_GET_IID(nsIURIContentListener))) {
     *aSink = mContentListener;
   } else if ((aIID.Equals(NS_GET_IID(nsIScriptGlobalObject)) ||
               aIID.Equals(NS_GET_IID(nsIGlobalObject)) ||
-              aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter)) ||
-              aIID.Equals(NS_GET_IID(nsIDOMWindow))) &&
+              aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter))) &&
              NS_SUCCEEDED(EnsureScriptEnvironment())) {
     return mScriptGlobal->QueryInterface(aIID, aSink);
   } else if (aIID.Equals(NS_GET_IID(nsIDOMDocument)) &&
              NS_SUCCEEDED(EnsureContentViewer())) {
     nsCOMPtr<nsIDOMDocument> doc =
       do_QueryInterface(mContentViewer->GetDocument());
     doc.forget(aSink);
     return *aSink ? NS_OK : NS_NOINTERFACE;

--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -358,18 +358,17 @@ public:
     if (!mWindow)
       return NS_OK;
     return mWindow->Observe(aSubject, aTopic, aData);
   }
   void Forget() { mWindow = nullptr; }
   NS_IMETHOD GetInterface(const nsIID& aIID, void** aResult) override
   {
     if (mWindow) {
-      if (aIID.Equals(NS_GET_IID(nsIDOMWindow)) ||
-          aIID.Equals(NS_GET_IID(nsPIDOMWindowInner))) {
+      if (aIID.Equals(NS_GET_IID(nsPIDOMWindowInner))) {
         return mWindow->QueryInterface(aIID, aResult);
       }
       if (aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter))) {
         return mWindow->GetOuterWindow()->QueryInterface(aIID, aResult);
       }
     }
     return NS_NOINTERFACE;
   }
@@ -1330,17 +1329,16 @@ nsGlobalWindowInner::FreeInnerObjects()
 //*****************************************************************************
 // nsGlobalWindowInner::nsISupports
 //*****************************************************************************
 
 // QueryInterface implementation for nsGlobalWindowInner
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsGlobalWindowInner)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, EventTarget)
-  NS_INTERFACE_MAP_ENTRY(nsIDOMWindow)
   NS_INTERFACE_MAP_ENTRY(nsIGlobalObject)
   NS_INTERFACE_MAP_ENTRY(nsIScriptGlobalObject)
   NS_INTERFACE_MAP_ENTRY(nsIScriptObjectPrincipal)
   NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
   if (aIID.Equals(NS_GET_IID(nsPIDOMWindowInner))) {
     foundInterface = static_cast<nsPIDOMWindowInner*>(this);
   } else
   if (aIID.Equals(NS_GET_IID(nsIDOMChromeWindow)) && IsChromeWindow()) {

--- a/dom/base/nsGlobalWindowInner.h
+++ b/dom/base/nsGlobalWindowInner.h
@@ -201,17 +201,16 @@ ImplCycleCollectionTraverse(nsCycleColle
 // also contain all inner window objects that are still in memory (and in
 // reality all inner window object's lists also contain its outer and all other
 // inner windows belonging to the same outer window, but that's an unimportant
 // side effect of inheriting PRCList).
 
 class nsGlobalWindowInner final
   : public mozilla::dom::EventTarget
   , public nsPIDOMWindowInner
-  , private nsIDOMWindow
   // NOTE: This interface is private, as it's only
   // implemented on chrome windows.
   , private nsIDOMChromeWindow
   , public nsIScriptGlobalObject
   , public nsIScriptObjectPrincipal
   , public nsSupportsWeakReference
   , public nsIInterfaceRequestor
   , public PRCListStr
@@ -294,19 +293,16 @@ public:
 
   virtual nsIScriptContext *GetScriptContext() override;
 
   virtual bool IsBlackForCC(bool aTracingNeeded = true) override;
 
   // nsIScriptObjectPrincipal
   virtual nsIPrincipal* GetPrincipal() override;
 
-  // nsIDOMWindow
-  NS_DECL_NSIDOMWINDOW
-
   // nsIDOMChromeWindow (only implemented on chrome windows)
   NS_DECL_NSIDOMCHROMEWINDOW
 
   void CaptureEvents();
   void ReleaseEvents();
   void Dump(const nsAString& aStr);
   void SetResizable(bool aResizable) const;
 

--- a/dom/base/nsGlobalWindowOuter.cpp
+++ b/dom/base/nsGlobalWindowOuter.cpp
@@ -1074,17 +1074,16 @@ nsGlobalWindowOuter::ClearControllers()
 //*****************************************************************************
 // nsGlobalWindowOuter::nsISupports
 //*****************************************************************************
 
 // QueryInterface implementation for nsGlobalWindowOuter
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsGlobalWindowOuter)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, EventTarget)
-  NS_INTERFACE_MAP_ENTRY(nsIDOMWindow)
   NS_INTERFACE_MAP_ENTRY(nsIGlobalObject)
   NS_INTERFACE_MAP_ENTRY(nsIScriptGlobalObject)
   NS_INTERFACE_MAP_ENTRY(nsIScriptObjectPrincipal)
   NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
   if (aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter))) {
     foundInterface = static_cast<nsPIDOMWindowOuter*>(this);
   } else
   if (aIID.Equals(NS_GET_IID(nsIDOMChromeWindow)) && IsChromeWindow()) {

--- a/dom/base/nsGlobalWindowOuter.h
+++ b/dom/base/nsGlobalWindowOuter.h
@@ -157,17 +157,16 @@ extern const js::Class OuterWindowProxyC
 // also contain all inner window objects that are still in memory (and in
 // reality all inner window object's lists also contain its outer and all other
 // inner windows belonging to the same outer window, but that's an unimportant
 // side effect of inheriting PRCList).
 
 class nsGlobalWindowOuter final
   : public mozilla::dom::EventTarget
   , public nsPIDOMWindowOuter
-  , private nsIDOMWindow
     // NOTE: This interface is private, as it's only
     // implemented on chrome windows.
   , private nsIDOMChromeWindow
   , public nsIScriptGlobalObject
   , public nsIScriptObjectPrincipal
   , public nsSupportsWeakReference
   , public nsIInterfaceRequestor
   , public PRCListStr
@@ -249,19 +248,16 @@ public:
 
   void PoisonOuterWindowProxy(JSObject *aObject);
 
   virtual bool IsBlackForCC(bool aTracingNeeded = true) override;
 
   // nsIScriptObjectPrincipal
   virtual nsIPrincipal* GetPrincipal() override;
 
-  // nsIDOMWindow
-  NS_DECL_NSIDOMWINDOW
-
   // nsIDOMChromeWindow (only implemented on chrome windows)
   NS_DECL_NSIDOMCHROMEWINDOW
 
   mozilla::dom::ChromeMessageBroadcaster* GetMessageManager();
   mozilla::dom::ChromeMessageBroadcaster* GetGroupMessageManager(const nsAString& aGroup);
 
   nsresult
   OpenJS(const nsAString& aUrl, const nsAString& aName,

--- a/dom/base/nsPIDOMWindow.h
+++ b/dom/base/nsPIDOMWindow.h
@@ -2,40 +2,42 @@
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* 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/. */
 
 #ifndef nsPIDOMWindow_h__
 #define nsPIDOMWindow_h__
 
-#include "nsIDOMWindow.h"
-
 #include "nsCOMPtr.h"
 #include "nsTArray.h"
 #include "mozilla/dom/EventTarget.h"
 #include "mozilla/TaskCategory.h"
 #include "js/TypeDecls.h"
 #include "nsRefPtrHashtable.h"
 
 // Only fired for inner windows.
 #define DOM_WINDOW_DESTROYED_TOPIC "dom-window-destroyed"
 #define DOM_WINDOW_FROZEN_TOPIC "dom-window-frozen"
 #define DOM_WINDOW_THAWED_TOPIC "dom-window-thawed"
 
 class nsGlobalWindowInner;
 class nsGlobalWindowOuter;
 class nsIArray;
 class nsIContent;
+class nsIControllers;
 class nsICSSDeclaration;
+class nsIDOMOfflineResourceList;
+class nsIDOMWindowCollection;
 class nsIDocShell;
 class nsIDocShellLoadInfo;
 class nsIDocument;
 class nsIIdleObserver;
 class nsIPrincipal;
+class nsIPrompt;
 class nsIScriptTimeoutHandler;
 class nsISerialEventTarget;
 class nsIURI;
 class nsPIDOMWindowInner;
 class nsPIDOMWindowOuter;
 class nsPIWindowRoot;
 class nsXBLPrototypeHandler;
 

--- 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',
-    'nsIDOMWindow.idl',
     'nsIDOMWindowCollection.idl',
     'nsIDOMWindowUtils.idl',
     'nsIFocusManager.idl',
     'nsIIdleObserver.idl',
     'nsIQueryContentEventResult.idl',
     'nsIRemoteBrowser.idl',
     'nsIServiceWorkerManager.idl',
     'nsIStructuredCloneContainer.idl',

deleted file mode 100644
--- a/dom/interfaces/base/nsIDOMWindow.idl
+++ /dev/null
@@ -1,20 +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 "domstubs.idl"
-
-interface nsIControllers;
-interface nsIDOMOfflineResourceList;
-interface nsIPrompt;
-interface nsIVariant;
-
-/**
- * Empty interface for compatibility with older versions.
- * @deprecated Use WebIDL for script visible features,
- *             nsPIDOMWindow for C++ callers.
- */
-
-[scriptable, uuid(b8343993-0383-4add-9930-ad176b189240)]
-interface nsIDOMWindow : nsISupports {};

--- a/dom/webidl/Window.webidl
+++ b/dom/webidl/Window.webidl
@@ -313,17 +313,17 @@ partial interface Window {
   /**
    * This method is here for backwards compatibility with 4.x only,
    * its implementation is a no-op
    */
   void                      setResizable(boolean resizable);
 
   /**
    * This is the scriptable version of
-   * nsIDOMWindow::openDialog() that takes 3 optional
+   * Window::openDialog() that takes 3 optional
    * arguments, plus any additional arguments are passed on as
    * arguments on the dialog's window object (window.arguments).
    */
   [Throws, ChromeOnly] WindowProxy? openDialog(optional DOMString url = "",
                                                optional DOMString name = "",
                                                optional DOMString options = "",
                                                any... extraArguments);
 
@@ -332,17 +332,17 @@ partial interface Window {
    ChromeOnly,
 #endif
    NonEnumerable, Replaceable, Throws, NeedsCallerType]
   readonly attribute object? content;
 
   [Throws, ChromeOnly] any getInterface(IID iid);
 
   /**
-   * Same as nsIDOMWindow.windowRoot, useful for event listener targeting.
+   * Same as Window.windowRoot, useful for event listener targeting.
    */
   [ChromeOnly, Throws]
   readonly attribute WindowRoot? windowRoot;
 
   /**
    * ChromeOnly method to determine if a particular window should see console
    * reports from service workers of the given scope.
    */

--- a/testing/mochitest/tests/Harness_sanity/test_SpecialPowersExtension.html
+++ b/testing/mochitest/tests/Harness_sanity/test_SpecialPowersExtension.html
@@ -77,18 +77,18 @@ function starttest(){
 
   // Test a DOMWindowUtils method and property
   is(SpecialPowers.DOMWindowUtils.getClassName(window), "Proxy");
   is(SpecialPowers.DOMWindowUtils.docCharsetIsForced, false);
   
   // QueryInterface and getPrivilegedProps tests
   is(SpecialPowers.can_QI(SpecialPowers), false);
   ok(SpecialPowers.can_QI(window));
-  ok(SpecialPowers.do_QueryInterface(window, "nsIDOMWindow"));
-  is(SpecialPowers.getPrivilegedProps(SpecialPowers.do_QueryInterface(window, "nsIDOMWindow"), "document.nodeName"), "#document");
+  ok(SpecialPowers.do_QueryInterface(window, "nsISupports"));
+  is(SpecialPowers.getPrivilegedProps(SpecialPowers.do_QueryInterface(window, "nsISupports"), "document.nodeName"), "#document");
   
   //try to run garbage collection
   SpecialPowers.gc();
 
   //
   // Test the SpecialPowers wrapper.
   //
 

--- a/xpfe/appshell/nsContentTreeOwner.cpp
+++ b/xpfe/appshell/nsContentTreeOwner.cpp
@@ -10,17 +10,16 @@
 #include "nsXULWindow.h"
 
 // Helper Classes
 #include "nsIServiceManager.h"
 #include "nsAutoPtr.h"
 
 // Interfaces needed to be included
 #include "nsIDOMNode.h"
-#include "nsIDOMWindow.h"
 #include "nsIDOMChromeWindow.h"
 #include "nsIBrowserDOMWindow.h"
 #include "nsIEmbeddingSiteWindow.h"
 #include "nsIPrompt.h"
 #include "nsIAuthPrompt.h"
 #include "nsIWindowMediator.h"
 #include "nsIXULBrowserWindow.h"
 #include "nsIPrincipal.h"
@@ -138,18 +137,17 @@ NS_IMETHODIMP nsContentTreeOwner::GetInt
     NS_ENSURE_STATE(mXULWindow);
     nsCOMPtr<nsIDocShell> shell;
     mXULWindow->GetDocShell(getter_AddRefs(shell));
     if (shell)
       return shell->QueryInterface(aIID, aSink);
     return NS_ERROR_FAILURE;
   }
 
-  if (aIID.Equals(NS_GET_IID(nsIDOMWindow)) ||
-      aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter))) {
+  if (aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter))) {
     NS_ENSURE_STATE(mXULWindow);
     nsCOMPtr<nsIDocShellTreeItem> shell;
     mXULWindow->GetPrimaryContentShell(getter_AddRefs(shell));
     if (shell) {
       nsCOMPtr<nsIInterfaceRequestor> thing(do_QueryInterface(shell));
       if (thing)
         return thing->GetInterface(aIID, aSink);
     }

--- a/xpfe/appshell/nsXULWindow.cpp
+++ b/xpfe/appshell/nsXULWindow.cpp
@@ -152,23 +152,16 @@ NS_IMETHODIMP nsXULWindow::GetInterface(
   if (aIID.Equals(NS_GET_IID(nsIAuthPrompt))) {
     rv = EnsureAuthPrompter();
     if (NS_FAILED(rv)) return rv;
     return mAuthPrompter->QueryInterface(aIID, aSink);
   }
   if (aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter))) {
     return GetWindowDOMWindow(reinterpret_cast<nsPIDOMWindowOuter**>(aSink));
   }
-  if (aIID.Equals(NS_GET_IID(nsIDOMWindow))) {
-    nsCOMPtr<nsPIDOMWindowOuter> window = nullptr;
-    rv = GetWindowDOMWindow(getter_AddRefs(window));
-    nsCOMPtr<nsIDOMWindow> domWindow = do_QueryInterface(window);
-    domWindow.forget(aSink);
-    return rv;
-  }
   if (aIID.Equals(NS_GET_IID(nsIWebBrowserChrome)) &&
     NS_SUCCEEDED(EnsureContentTreeOwner()) &&
     NS_SUCCEEDED(mContentTreeOwner->QueryInterface(aIID, aSink)))
     return NS_OK;
 
   if (aIID.Equals(NS_GET_IID(nsIEmbeddingSiteWindow)) &&
     NS_SUCCEEDED(EnsureContentTreeOwner()) &&
     NS_SUCCEEDED(mContentTreeOwner->QueryInterface(aIID, aSink)))