--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -985,18 +985,17 @@ nsDocShell::GetInterface(const nsIID& aI
     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(mozIDOMWindowProxy)) ||
-              aIID.Equals(NS_GET_IID(nsIDOMWindow)) ||
-              aIID.Equals(NS_GET_IID(nsIDOMWindowInternal))) &&
+              aIID.Equals(NS_GET_IID(nsIDOMWindow))) &&
              NS_SUCCEEDED(EnsureScriptEnvironment())) {
     return mScriptGlobal->QueryInterface(aIID, aSink);
   } else if (aIID.Equals(NS_GET_IID(nsIDOMDocument)) &&
              NS_SUCCEEDED(EnsureContentViewer())) {
     mContentViewer->GetDOMDocument((nsIDOMDocument**)aSink);
     return *aSink ? NS_OK : NS_NOINTERFACE;
   } else if (aIID.Equals(NS_GET_IID(nsIDocument)) &&
              NS_SUCCEEDED(EnsureContentViewer())) {

--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -288,17 +288,16 @@ using mozilla::BasePrincipal;
 using mozilla::OriginAttributes;
 using mozilla::TimeStamp;
 using mozilla::TimeDuration;
 using mozilla::dom::cache::CacheStorage;
 
 static LazyLogModule gDOMLeakPRLog("DOMLeak");
 
 nsGlobalWindow::WindowByIdTable *nsGlobalWindow::sWindowsById = nullptr;
-bool nsGlobalWindow::sWarnedAboutWindowInternal = false;
 bool nsGlobalWindow::sIdleObserversAPIFuzzTimeDisabled = false;
 
 static int32_t              gRefCnt                    = 0;
 static int32_t              gOpenPopupSpamCount        = 0;
 static PopupControlState    gPopupControlState         = openAbused;
 static bool                 gMouseDown                 = false;
 static bool                 gDragServiceDisabled       = false;
 static FILE                *gDumpFile                  = nullptr;
@@ -2217,26 +2216,16 @@ nsGlobalWindow::FreeInnerObjects()
 //*****************************************************************************
 
 // QueryInterface implementation for nsGlobalWindow
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsGlobalWindow)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   // Make sure this matches the cast in nsGlobalWindow::FromWrapper()
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMEventTarget)
   NS_INTERFACE_MAP_ENTRY(nsIDOMWindow)
-  if (aIID.Equals(NS_GET_IID(nsIDOMWindowInternal))) {
-    foundInterface = static_cast<nsIDOMWindowInternal*>(this);
-    if (!sWarnedAboutWindowInternal) {
-      sWarnedAboutWindowInternal = true;
-      nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
-                                      NS_LITERAL_CSTRING("Extensions"), mDoc,
-                                      nsContentUtils::eDOM_PROPERTIES,
-                                      "nsIDOMWindowInternalWarning");
-    }
-  } else
   NS_INTERFACE_MAP_ENTRY(nsIGlobalObject)
   NS_INTERFACE_MAP_ENTRY(nsIScriptGlobalObject)
   NS_INTERFACE_MAP_ENTRY(nsIScriptObjectPrincipal)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventTarget)
   NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
   if (aIID.Equals(NS_GET_IID(nsPIDOMWindowInner))) {
     foundInterface = AsInner();
   } else

--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -256,17 +256,17 @@ private:
 // the other by making it possible to convert types through the C++ type system
 // instead of our accessor methods (AsInner and AsOuter) that do dynamic
 // checking. So we inherit from nsPIDOMWindow<nsISupports>, which is also
 // identical to both nsPIDOMWindowInner and nsPIDOMWindowOuter, but not
 // convertible to either.
 
 class nsGlobalWindow : public mozilla::dom::EventTarget,
                        public nsPIDOMWindow<nsISupports>,
-                       private nsIDOMWindowInternal,
+                       private nsIDOMWindow,
                        public nsIScriptGlobalObject,
                        public nsIScriptObjectPrincipal,
                        public nsSupportsWeakReference,
                        public nsIInterfaceRequestor,
                        public PRCListStr
 {
 public:
   typedef mozilla::TimeStamp TimeStamp;
@@ -2082,17 +2082,16 @@ protected:
   friend class nsDOMScriptableHelper;
   friend class nsDOMWindowUtils;
   friend class mozilla::dom::PostMessageEvent;
   friend class DesktopNotification;
   friend class mozilla::dom::TimeoutManager;
   friend class IdleRequestExecutor;
 
   static WindowByIdTable* sWindowsById;
-  static bool sWarnedAboutWindowInternal;
 };
 
 inline nsISupports*
 ToSupports(nsGlobalWindow *p)
 {
     return static_cast<nsIDOMEventTarget*>(p);
 }
 

--- a/dom/interfaces/base/nsIDOMWindow.idl
+++ b/dom/interfaces/base/nsIDOMWindow.idl
@@ -15,15 +15,8 @@ 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 {};
-
-/**
- * Empty interface for compatibility with older versions.
- * @deprecated Use nsIDOMWindow instead
- */
-[scriptable, uuid(8c589e65-3237-4cd1-8bad-c5c47135e79b)]
-interface nsIDOMWindowInternal : nsIDOMWindow {};

--- a/dom/locales/en-US/chrome/dom/dom.properties
+++ b/dom/locales/en-US/chrome/dom/dom.properties
@@ -57,17 +57,16 @@ SetAttributeNodeNSWarning=Use of setAttr
 RemoveAttributeNodeWarning=Use of removeAttributeNode() is deprecated. Use removeAttribute() instead.
 CreateAttributeWarning=Use of document.createAttribute() is deprecated. Use element.setAttribute() instead.
 CreateAttributeNSWarning=Use of document.createAttributeNS() is deprecated. Use element.setAttributeNS() instead.
 NodeValueWarning=Use of attributes’ nodeValue attribute is deprecated. Use value instead.
 TextContentWarning=Use of attributes’ textContent attribute is deprecated. Use value instead.
 EnablePrivilegeWarning=Use of enablePrivilege is deprecated.  Please use code that runs with the system principal (e.g. an extension) instead.
 nsIJSONDecodeDeprecatedWarning=nsIJSON.decode is deprecated.  Please use JSON.parse instead.
 nsIJSONEncodeDeprecatedWarning=nsIJSON.encode is deprecated.  Please use JSON.stringify instead.
-nsIDOMWindowInternalWarning=Use of nsIDOMWindowInternal is deprecated. Use nsIDOMWindow instead.
 FullscreenDeniedDisabled=Request for fullscreen was denied because Fullscreen API is disabled by user preference.
 FullscreenDeniedFocusedPlugin=Request for fullscreen was denied because a windowed plugin is focused.
 FullscreenDeniedHidden=Request for fullscreen was denied because the document is no longer visible.
 FullscreenDeniedContainerNotAllowed=Request for fullscreen was denied because at least one of the document’s containing elements is not an iframe or does not have an “allowfullscreen” attribute.
 FullscreenDeniedNotInputDriven=Request for fullscreen was denied because Element.requestFullscreen() was not called from inside a short running user-generated event handler.
 FullscreenDeniedNotHTMLSVGOrMathML=Request for fullscreen was denied because requesting element is not <svg>, <math>, or an HTML element.
 FullscreenDeniedNotInDocument=Request for fullscreen was denied because requesting element is no longer in its document.
 FullscreenDeniedMovedDocument=Request for fullscreen was denied because requesting element has moved document.

--- a/mobile/android/extensions/flyweb/bootstrap.js
+++ b/mobile/android/extensions/flyweb/bootstrap.js
@@ -57,17 +57,17 @@ function Factory(component) {
   }
   Object.freeze(this);
   this.register();
 }
 
 let windowListener = {
   onOpenWindow: function(aWindow) {
     // Wait for the window to finish loading
-    let domWindow = aWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowInternal || Ci.nsIDOMWindow);
+    let domWindow = aWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindow);
     domWindow.addEventListener("UIReady", function() {
       loadIntoWindow(domWindow);
     }, {once: true});
   },
 
   onCloseWindow: function(aWindow) {},
   onWindowTitleChange: function(aWindow, aTitle) {}
 };

--- a/xpfe/appshell/nsXULWindow.cpp
+++ b/xpfe/appshell/nsXULWindow.cpp
@@ -160,23 +160,16 @@ NS_IMETHODIMP nsXULWindow::GetInterface(
   }
   if (aIID.Equals(NS_GET_IID(nsIDOMWindow))) {
     nsCOMPtr<mozIDOMWindowProxy> window = nullptr;
     rv = GetWindowDOMWindow(getter_AddRefs(window));
     nsCOMPtr<nsIDOMWindow> domWindow = do_QueryInterface(window);
     domWindow.forget(aSink);
     return rv;
   }
-  if (aIID.Equals(NS_GET_IID(nsIDOMWindowInternal))) {
-    nsCOMPtr<mozIDOMWindowProxy> window = nullptr;
-    rv = GetWindowDOMWindow(getter_AddRefs(window));
-    nsCOMPtr<nsIDOMWindowInternal> domWindowInternal = do_QueryInterface(window);
-    domWindowInternal.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)))