Bug 1470510 - Rename nsXULWindow and nsIXULWindow to AppWindow and nsIAppWindow. r=smaug

nsXULWindow is no longer XUL specific and is somewhat confusing name. Differential Revision: https://phabricator.services.mozilla.com/D51486 --HG-- rename : xpfe/appshell/nsXULWindow.cpp => xpfe/appshell/AppWindow.cpp rename : xpfe/appshell/nsXULWindow.h => xpfe/appshell/AppWindow.h rename : xpfe/appshell/nsIXULWindow.idl => xpfe/appshell/nsIAppWindow.idl extra : moz-landing-system : lando
2019-11-05 17:56:28 +00:00 · 2019-11-05 17:56:28 +00:00 · eafc9e3293
--- a/accessible/generic/RootAccessible.cpp
+++ b/accessible/generic/RootAccessible.cpp
@ -45,7 +45,7 @@
 #include "nsGlobalWindow.h"

 #ifdef MOZ_XUL
-#  include "nsIXULWindow.h"
+#  include "nsIAppWindow.h"
 #endif

 using namespace mozilla;
@ -97,18 +97,18 @@ role RootAccessible::NativeRole() const {
 uint32_t RootAccessible::GetChromeFlags() const {
  // Return the flag set for the top level window as defined
  // by nsIWebBrowserChrome::CHROME_WINDOW_[FLAGNAME]
-  // Not simple: nsIXULWindow is not just a QI from nsIDOMWindow
+  // Not simple: nsIAppWindow is not just a QI from nsIDOMWindow
  nsCOMPtr<nsIDocShell> docShell = nsCoreUtils::GetDocShellFor(mDocumentNode);
  NS_ENSURE_TRUE(docShell, 0);
  nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
  docShell->GetTreeOwner(getter_AddRefs(treeOwner));
  NS_ENSURE_TRUE(treeOwner, 0);
-  nsCOMPtr<nsIXULWindow> xulWin(do_GetInterface(treeOwner));
-  if (!xulWin) {
+  nsCOMPtr<nsIAppWindow> appWin(do_GetInterface(treeOwner));
+  if (!appWin) {
    return 0;
  }
  uint32_t chromeFlags;
-  xulWin->GetChromeFlags(&chromeFlags);
+  appWin->GetChromeFlags(&chromeFlags);
  return chromeFlags;
 }
 #endif
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@ -1759,7 +1759,7 @@ var gBrowserInit = {
    // This needs setting up before we create the first remote browser.
    window.docShell.treeOwner
      .QueryInterface(Ci.nsIInterfaceRequestor)
-      .getInterface(Ci.nsIXULWindow).XULBrowserWindow = window.XULBrowserWindow;
+      .getInterface(Ci.nsIAppWindow).XULBrowserWindow = window.XULBrowserWindow;
    window.browserDOMWindow = new nsBrowserAccess();

    gBrowser = window._gBrowser;
@ -2534,7 +2534,7 @@ var gBrowserInit = {
    window.XULBrowserWindow = null;
    window.docShell.treeOwner
      .QueryInterface(Ci.nsIInterfaceRequestor)
-      .getInterface(Ci.nsIXULWindow).XULBrowserWindow = null;
+      .getInterface(Ci.nsIAppWindow).XULBrowserWindow = null;
    window.browserDOMWindow = null;
  },
 };
--- a/browser/components/BrowserGlue.jsm
+++ b/browser/components/BrowserGlue.jsm
@ -449,11 +449,11 @@ let LEGACY_ACTORS = {
    // Set the size to use when the user leaves the maximized mode.
    // The persisted size is the outer size, but the height/width
    // attributes set the inner size.
-    let xulWin = win.docShell.treeOwner
+    let appWin = win.docShell.treeOwner
      .QueryInterface(Ci.nsIInterfaceRequestor)
-      .getInterface(Ci.nsIXULWindow);
-    height -= xulWin.outerToInnerHeightDifferenceInCSSPixels;
-    width -= xulWin.outerToInnerWidthDifferenceInCSSPixels;
+      .getInterface(Ci.nsIAppWindow);
+    height -= appWin.outerToInnerHeightDifferenceInCSSPixels;
+    width -= appWin.outerToInnerWidthDifferenceInCSSPixels;
    docElt.setAttribute("height", height);
    docElt.setAttribute("width", width);
  } else {
--- a/browser/components/downloads/DownloadsTaskbar.jsm
+++ b/browser/components/downloads/DownloadsTaskbar.jsm
@ -131,7 +131,7 @@ var DownloadsTaskbar = {
    // Activate the indicator on the specified window.
    let docShell = aWindow.docShell.treeOwner
      .QueryInterface(Ci.nsIInterfaceRequestor)
-      .getInterface(Ci.nsIXULWindow).docShell;
+      .getInterface(Ci.nsIAppWindow).docShell;
    this._taskbarProgress = gWinTaskbar.getTaskbarProgress(docShell);

    // If the DownloadSummary object has already been created, we should update
--- a/browser/components/extensions/parent/ext-browser.js
+++ b/browser/components/extensions/parent/ext-browser.js
@ -1009,7 +1009,7 @@ class Window extends WindowBase {
  }

  get alwaysOnTop() {
-    return this.xulWindow.zLevel >= Ci.nsIXULWindow.raisedZ;
+    return this.appWindow.zLevel >= Ci.nsIAppWindow.raisedZ;
  }

  get isLastFocused() {
--- a/browser/components/extensions/test/browser/browser_ext_windows_create.js
+++ b/browser/components/extensions/test/browser/browser_ext_windows_create.js
@ -172,7 +172,7 @@ add_task(async function testWindowCreate() {
    if (expected.chromeFlags) {
      let { chromeFlags } = latestWindow.docShell.treeOwner
        .QueryInterface(Ci.nsIInterfaceRequestor)
-        .getInterface(Ci.nsIXULWindow);
+        .getInterface(Ci.nsIAppWindow);
      for (let flag of expected.chromeFlags) {
        ok(
          chromeFlags & Ci.nsIWebBrowserChrome[flag],
--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_context_and_chromeFlags.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_context_and_chromeFlags.js
@ -2,7 +2,7 @@

 /**
 * Given some window in the parent process, ensure that
- * the nsIXULWindow has the CHROME_PRIVATE_WINDOW chromeFlag,
+ * the nsIAppWindow has the CHROME_PRIVATE_WINDOW chromeFlag,
 * and that the usePrivateBrowsing property is set to true on
 * both the window's nsILoadContext, as well as on the initial
 * browser's content docShell nsILoadContext.
@ -15,7 +15,7 @@ function assertWindowIsPrivate(win) {
  let winDocShell = win.docShell;
  let chromeFlags = winDocShell.treeOwner
    .QueryInterface(Ci.nsIInterfaceRequestor)
-    .getInterface(Ci.nsIXULWindow).chromeFlags;
+    .getInterface(Ci.nsIAppWindow).chromeFlags;

  if (!win.gBrowser.selectedBrowser.hasContentOpener) {
    Assert.ok(
--- a/browser/components/search/SearchTelemetry.jsm
+++ b/browser/components/search/SearchTelemetry.jsm
@ -244,10 +244,10 @@ class TelemetryHandler {
   * This is called when a new window is opened, and handles registration of
   * that window if it is a browser window.
   *
-   * @param {nsIXULWindow} xulWin The xul window that was opened.
+   * @param {nsIAppWindow} appWin The xul window that was opened.
   */
-  onOpenWindow(xulWin) {
-    let win = xulWin.docShell.domWindow;
+  onOpenWindow(appWin) {
+    let win = appWin.docShell.domWindow;
    win.addEventListener(
      "load",
      () => {
@ -268,10 +268,10 @@ class TelemetryHandler {
   * Listener that is called when a window is closed, and handles deregistration of
   * that window if it is a browser window.
   *
-   * @param {nsIXULWindow} xulWin The xul window that was closed.
+   * @param {nsIAppWindow} appWin The xul window that was closed.
   */
-  onCloseWindow(xulWin) {
-    let win = xulWin.docShell.domWindow;
+  onCloseWindow(appWin) {
+    let win = appWin.docShell.domWindow;

    if (
      win.document.documentElement.getAttribute("windowtype") !=
--- a/browser/components/sessionstore/SessionStore.jsm
+++ b/browser/components/sessionstore/SessionStore.jsm
@ -5259,7 +5259,7 @@ var SessionStoreInternal = {
  },

  /**
-   * on popup windows, the XULWindow's attributes seem not to be set correctly
+   * on popup windows, the AppWindow's attributes seem not to be set correctly
   * we use thus JSDOMWindow attributes for sizemode and normal window attributes
   * (and hope for reasonable values when maximized/minimized - since then
   * outerWidth/outerHeight aren't the dimensions of the restored window)
@ -5298,13 +5298,13 @@ var SessionStoreInternal = {
        }
        // Width and height attribute report the inner size, but we want
        // to store the outer size, so add the difference.
-        let xulWin = aWindow.docShell.treeOwner
+        let appWin = aWindow.docShell.treeOwner
          .QueryInterface(Ci.nsIInterfaceRequestor)
-          .getInterface(Ci.nsIXULWindow);
+          .getInterface(Ci.nsIAppWindow);
        let diff =
          aAttribute == "width"
-            ? xulWin.outerToInnerWidthDifferenceInCSSPixels
-            : xulWin.outerToInnerHeightDifferenceInCSSPixels;
+            ? appWin.outerToInnerWidthDifferenceInCSSPixels
+            : appWin.outerToInnerHeightDifferenceInCSSPixels;
        return attr + diff;
      }
    }
--- a/browser/components/tests/startupRecorder.js
+++ b/browser/components/tests/startupRecorder.js
@ -123,8 +123,8 @@ startupRecorder.prototype = {
    // not other types (for example, the gfx sanity test window)
    if (topic == firstPaintNotification) {
      // In the case we're handling xul-window-visible, we'll have been handed
-      // an nsIXULWindow instead of an nsIDOMWindow.
-      if (subject instanceof Ci.nsIXULWindow) {
+      // an nsIAppWindow instead of an nsIDOMWindow.
+      if (subject instanceof Ci.nsIAppWindow) {
        subject = subject
          .QueryInterface(Ci.nsIInterfaceRequestor)
          .getInterface(Ci.nsIDOMWindow);
--- a/devtools/server/actors/webbrowser.js
+++ b/devtools/server/actors/webbrowser.js
@ -289,12 +289,12 @@ BrowserTabList.prototype._getChildren = function(window) {
 };

 BrowserTabList.prototype.getList = function(browserActorOptions) {
-  const topXULWindow = Services.wm.getMostRecentWindow(
+  const topAppWindow = Services.wm.getMostRecentWindow(
    DebuggerServer.chromeWindowType
  );
  let selectedBrowser = null;
-  if (topXULWindow) {
-    selectedBrowser = this._getSelectedBrowser(topXULWindow);
+  if (topAppWindow) {
+    selectedBrowser = this._getSelectedBrowser(topAppWindow);
  }

  // As a sanity check, make sure all the actors presently in our map get
@ -416,11 +416,11 @@ BrowserTabList.prototype.getTab = function(
    });
  }

-  const topXULWindow = Services.wm.getMostRecentWindow(
+  const topAppWindow = Services.wm.getMostRecentWindow(
    DebuggerServer.chromeWindowType
  );
-  if (topXULWindow) {
-    const selectedBrowser = this._getSelectedBrowser(topXULWindow);
+  if (topAppWindow) {
+    const selectedBrowser = this._getSelectedBrowser(topAppWindow);
    return this._getActorForBrowser(selectedBrowser, browserActorOptions);
  }
  return Promise.reject({
@ -781,7 +781,7 @@ BrowserTabList.prototype.onOpenWindow = DevToolsUtils.makeInfallible(function(
 BrowserTabList.prototype.onCloseWindow = DevToolsUtils.makeInfallible(function(
  window
 ) {
-  if (window instanceof Ci.nsIXULWindow) {
+  if (window instanceof Ci.nsIAppWindow) {
    window = window.docShell.domWindow;
  }

--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@ -4984,7 +4984,7 @@ nsDocShell::SetParentNativeWindow(nativeWindow aParentNativeWindow) {

 NS_IMETHODIMP
 nsDocShell::GetNativeHandle(nsAString& aNativeHandle) {
-  // the nativeHandle should be accessed from nsIXULWindow
+  // the nativeHandle should be accessed from nsIAppWindow
  return NS_ERROR_NOT_IMPLEMENTED;
 }

--- a/docshell/base/nsDocShellTreeOwner.cpp
+++ b/docshell/base/nsDocShellTreeOwner.cpp
@ -360,7 +360,7 @@ nsDocShellTreeOwner::SizeShellTo(nsIDocShellTreeItem* aShellItem, int32_t aCX,
    if (browserChild) {
      // The XUL window to resize is in the parent process, but there we
      // won't be able to get aShellItem to do the hack in
-      // nsXULWindow::SizeShellTo, so let's send the width and height of
+      // AppWindow::SizeShellTo, so let's send the width and height of
      // aShellItem too.
      nsCOMPtr<nsIBaseWindow> shellAsWin(do_QueryInterface(aShellItem));
      NS_ENSURE_TRUE(shellAsWin, NS_ERROR_FAILURE);
@ -588,7 +588,7 @@ nsDocShellTreeOwner::SetParentNativeWindow(nativeWindow aParentNativeWindow) {

 NS_IMETHODIMP
 nsDocShellTreeOwner::GetNativeHandle(nsAString& aNativeHandle) {
-  // the nativeHandle should be accessed from nsIXULWindow
+  // the nativeHandle should be accessed from nsIAppWindow
  return NS_ERROR_NOT_IMPLEMENTED;
 }

--- a/docshell/test/navigation/browser_test-content-chromeflags.js
+++ b/docshell/test/navigation/browser_test-content-chromeflags.js
@ -33,7 +33,7 @@ add_task(async function() {

      let chromeFlags = win.docShell.treeOwner
        .QueryInterface(Ci.nsIInterfaceRequestor)
-        .getInterface(Ci.nsIXULWindow).chromeFlags;
+        .getInterface(Ci.nsIAppWindow).chromeFlags;

      let expected = CHROME_ALL;

--- a/dom/base/Document.cpp
+++ b/dom/base/Document.cpp
@ -312,7 +312,7 @@
 #ifdef MOZ_XUL
 #  include "mozilla/dom/XULBroadcastManager.h"
 #  include "mozilla/dom/XULPersist.h"
-#  include "nsIXULWindow.h"
+#  include "nsIAppWindow.h"
 #  include "nsIChromeRegistry.h"
 #  include "nsXULPrototypeDocument.h"
 #  include "nsXULCommandDispatcher.h"
@ -8381,7 +8381,7 @@ void Document::SetMayStartLayout(bool aMayStartLayout) {
    // Before starting layout, check whether we're a toplevel chrome
    // window.  If we are, setup some state so that we don't have to restyle
    // the whole tree after StartLayout.
-    if (nsCOMPtr<nsIXULWindow> win = GetXULWindowIfToplevelChrome()) {
+    if (nsCOMPtr<nsIAppWindow> win = GetAppWindowIfToplevelChrome()) {
      // We're the chrome document!
      win->BeforeStartLayout();
    }
@ -14275,23 +14275,23 @@ already_AddRefed<XPathResult> Document::Evaluate(
                                    aType, aResult, rv);
 }

-already_AddRefed<nsIXULWindow> Document::GetXULWindowIfToplevelChrome() const {
+already_AddRefed<nsIAppWindow> Document::GetAppWindowIfToplevelChrome() const {
  nsCOMPtr<nsIDocShellTreeItem> item = GetDocShell();
  if (!item) {
    return nullptr;
  }
  nsCOMPtr<nsIDocShellTreeOwner> owner;
  item->GetTreeOwner(getter_AddRefs(owner));
-  nsCOMPtr<nsIXULWindow> xulWin = do_GetInterface(owner);
-  if (!xulWin) {
+  nsCOMPtr<nsIAppWindow> appWin = do_GetInterface(owner);
+  if (!appWin) {
    return nullptr;
  }
-  nsCOMPtr<nsIDocShell> xulWinShell;
-  xulWin->GetDocShell(getter_AddRefs(xulWinShell));
-  if (!SameCOMIdentity(xulWinShell, item)) {
+  nsCOMPtr<nsIDocShell> appWinShell;
+  appWin->GetDocShell(getter_AddRefs(appWinShell));
+  if (!SameCOMIdentity(appWinShell, item)) {
    return nullptr;
  }
-  return xulWin.forget();
+  return appWin.forget();
 }

 Document* Document::GetTopLevelContentDocument() {
--- a/dom/base/Document.h
+++ b/dom/base/Document.h
@ -133,7 +133,7 @@ class nsWindowSizes;
 class nsDOMCaretPosition;
 class nsViewportInfo;
 class nsIGlobalObject;
-class nsIXULWindow;
+class nsIAppWindow;
 class nsXULPrototypeDocument;
 class nsXULPrototypeElement;
 class PermissionDelegateHandler;
@ -3536,9 +3536,9 @@ class Document : public nsINode,
  Document* GetTopLevelContentDocument();
  const Document* GetTopLevelContentDocument() const;

-  // Returns the associated XUL window if this is a top-level chrome document,
+  // Returns the associated app window if this is a top-level chrome document,
  // null otherwise.
-  already_AddRefed<nsIXULWindow> GetXULWindowIfToplevelChrome() const;
+  already_AddRefed<nsIAppWindow> GetAppWindowIfToplevelChrome() const;

  already_AddRefed<Element> CreateElement(
      const nsAString& aTagName, const ElementCreationOptionsOrString& aOptions,
--- a/dom/base/nsCCUncollectableMarker.cpp
+++ b/dom/base/nsCCUncollectableMarker.cpp
@ -18,7 +18,7 @@
 #include "nsISHEntry.h"
 #include "nsIWindowWatcher.h"
 #include "mozilla/Services.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIAppShellService.h"
 #include "nsAppShellCID.h"
 #include "nsContentUtils.h"
@ -351,7 +351,7 @@ nsresult nsCCUncollectableMarker::Observe(nsISupports* aSubject,
    bool hasHiddenWindow = false;
    appShell->GetHasHiddenWindow(&hasHiddenWindow);
    if (hasHiddenWindow) {
-      nsCOMPtr<nsIXULWindow> hw;
+      nsCOMPtr<nsIAppWindow> hw;
      appShell->GetHiddenWindow(getter_AddRefs(hw));
      nsCOMPtr<nsIDocShell> shell;
      hw->GetDocShell(getter_AddRefs(shell));
--- a/dom/base/nsFocusManager.cpp
+++ b/dom/base/nsFocusManager.cpp
@ -24,7 +24,7 @@
 #include "nsIWebNavigation.h"
 #include "nsCaret.h"
 #include "nsIBaseWindow.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsViewManager.h"
 #include "nsFrameSelection.h"
 #include "mozilla/dom/Document.h"
@ -700,10 +700,10 @@ nsFocusManager::WindowRaised(mozIDOMWindowProxy* aWindow) {
  NS_ASSERTION(currentWindow, "window raised with no window current");
  if (!currentWindow) return NS_OK;

-  // If there is no nsIXULWindow, then this is an embedded or child process
+  // If there is no nsIAppWindow, then this is an embedded or child process
  // window. Pass false for aWindowRaised so that commands get updated.
-  nsCOMPtr<nsIXULWindow> xulWin(do_GetInterface(baseWindow));
-  Focus(currentWindow, currentFocus, 0, true, false, xulWin != nullptr, true);
+  nsCOMPtr<nsIAppWindow> appWin(do_GetInterface(baseWindow));
+  Focus(currentWindow, currentFocus, 0, true, false, appWin != nullptr, true);

  return NS_OK;
 }
--- a/dom/base/nsFrameLoader.cpp
+++ b/dom/base/nsFrameLoader.cpp
@ -39,7 +39,7 @@
 #include "nsSubDocumentFrame.h"
 #include "nsError.h"
 #include "nsISHistory.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIMozBrowserFrame.h"
 #include "nsISHistory.h"
 #include "nsIScriptError.h"
@ -2598,7 +2598,7 @@ bool nsFrameLoader::TryRemoteBrowserInternal() {
      !parentOwner) {
    return false;
  }
-  nsCOMPtr<nsIXULWindow> window(do_GetInterface(parentOwner));
+  nsCOMPtr<nsIAppWindow> window(do_GetInterface(parentOwner));
  if (window && NS_FAILED(window->GetChromeFlags(&chromeFlags))) {
    return false;
  }
--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@ -160,7 +160,6 @@
 #include "mozilla/EventStateManager.h"
 #include "nsIObserverService.h"
 #include "nsFocusManager.h"
-#include "nsIXULWindow.h"
 #include "nsITimedChannel.h"
 #include "nsServiceManagerUtils.h"
 #ifdef MOZ_XUL
--- a/dom/base/nsGlobalWindowOuter.cpp
+++ b/dom/base/nsGlobalWindowOuter.cpp
@ -154,7 +154,7 @@
 #include "mozilla/EventStateManager.h"
 #include "nsIObserverService.h"
 #include "nsFocusManager.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsITimedChannel.h"
 #include "nsServiceManagerUtils.h"
 #include "mozilla/dom/CustomEvent.h"
@ -1546,7 +1546,7 @@ void nsGlobalWindowOuter::SetInitialPrincipalToSubject(
  // We should never create windows with an expanded principal.
  // If we have a system principal, make sure we're not using it for a content
  // docshell.
-  // NOTE: Please keep this logic in sync with nsXULWindow::Initialize().
+  // NOTE: Please keep this logic in sync with AppWindow::Initialize().
  if (nsContentUtils::IsExpandedPrincipal(newWindowPrincipal) ||
      (nsContentUtils::IsSystemPrincipal(newWindowPrincipal) &&
       GetDocShell()->ItemType() != nsIDocShellTreeItem::typeChrome)) {
@ -4404,9 +4404,9 @@ nsresult nsGlobalWindowOuter::SetFullscreenInternal(FullscreenReason aReason,
  // Prevent chrome documents which are still loading from resizing
  // the window after we set fullscreen mode.
  nsCOMPtr<nsIBaseWindow> treeOwnerAsWin = GetTreeOwnerWindow();
-  nsCOMPtr<nsIXULWindow> xulWin(do_GetInterface(treeOwnerAsWin));
-  if (aFullscreen && xulWin) {
-    xulWin->SetIntrinsicallySized(false);
+  nsCOMPtr<nsIAppWindow> appWin(do_GetInterface(treeOwnerAsWin));
+  if (aFullscreen && appWin) {
+    appWin->SetIntrinsicallySized(false);
  }

  // Set this before so if widget sends an event indicating its
@ -6795,10 +6795,10 @@ void nsGlobalWindowOuter::ActivateOrDeactivate(bool aActivate) {
    // Get the top level widget's nsGlobalWindowOuter
    nsCOMPtr<nsPIDOMWindowOuter> topLevelWindow;

-    // widgetListener should be a nsXULWindow
+    // widgetListener should be an AppWindow
    nsIWidgetListener* listener = topLevelWidget->GetWidgetListener();
    if (listener) {
-      nsCOMPtr<nsIXULWindow> window = listener->GetXULWindow();
+      nsCOMPtr<nsIAppWindow> window = listener->GetAppWindow();
      nsCOMPtr<nsIInterfaceRequestor> req(do_QueryInterface(window));
      topLevelWindow = do_GetInterface(req);
    }
--- a/dom/base/nsGlobalWindowOuter.h
+++ b/dom/base/nsGlobalWindowOuter.h
@ -56,6 +56,7 @@
 #include "nsCheapSets.h"
 #include "mozilla/dom/ImageBitmapSource.h"
 #include "mozilla/UniquePtr.h"
+#include "mozilla/dom/BrowsingContext.h"

 class nsDocShell;
 class nsIArray;
@ -89,7 +90,6 @@ class DOMEventTargetHelper;
 class ThrottledEventQueue;
 namespace dom {
 class BarProp;
-class BrowsingContext;
 struct ChannelPixelLayout;
 class Console;
 class Crypto;
--- a/dom/ipc/BrowserParent.cpp
+++ b/dom/ipc/BrowserParent.cpp
@ -72,7 +72,7 @@
 #include "nsIWebBrowserChrome.h"
 #include "nsIWebProtocolHandlerRegistrar.h"
 #include "nsIXULBrowserWindow.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsViewManager.h"
 #include "nsVariant.h"
 #include "nsIWidget.h"
@ -410,7 +410,7 @@ nsIXULBrowserWindow* BrowserParent::GetXULBrowserWindow() {
    return nullptr;
  }

-  nsCOMPtr<nsIXULWindow> window = do_GetInterface(treeOwner);
+  nsCOMPtr<nsIAppWindow> window = do_GetInterface(treeOwner);
  if (!window) {
    return nullptr;
  }
@ -798,9 +798,9 @@ mozilla::ipc::IPCResult BrowserParent::RecvSizeShellTo(
    height = mDimensions.height;
  }

-  nsCOMPtr<nsIXULWindow> xulWin(do_GetInterface(treeOwner));
-  NS_ENSURE_TRUE(xulWin, IPC_OK());
-  xulWin->SizeShellToWithLimit(width, height, aShellItemWidth,
+  nsCOMPtr<nsIAppWindow> appWin(do_GetInterface(treeOwner));
+  NS_ENSURE_TRUE(appWin, IPC_OK());
+  appWin->SizeShellToWithLimit(width, height, aShellItemWidth,
                               aShellItemHeight);

  return IPC_OK();
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@ -178,7 +178,7 @@
 #include "nsIURIFixup.h"
 #include "nsIURL.h"
 #include "nsIDocShellTreeOwner.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIDOMChromeWindow.h"
 #include "nsIWindowWatcher.h"
 #include "nsPIWindowWatcher.h"
--- a/dom/plugins/base/nsPluginHost.cpp
+++ b/dom/plugins/base/nsPluginHost.cpp
@ -2692,7 +2692,7 @@ static void CheckForDisabledWindows() {
  if (!wm) return;

  nsCOMPtr<nsISimpleEnumerator> windowList;
-  wm->GetXULWindowEnumerator(nullptr, getter_AddRefs(windowList));
+  wm->GetAppWindowEnumerator(nullptr, getter_AddRefs(windowList));
  if (!windowList) return;

  bool haveWindows;
--- a/dom/xul/XULPersist.cpp
+++ b/dom/xul/XULPersist.cpp
@ -13,7 +13,7 @@
 #  include "nsIStringEnumerator.h"
 #endif

-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"

 namespace mozilla {
 namespace dom {
@ -25,12 +25,12 @@ static bool IsRootElement(Element* aElement) {
 static bool ShouldPersistAttribute(Element* aElement, nsAtom* aAttribute) {
  if (IsRootElement(aElement)) {
    // This is not an element of the top document, its owner is
-    // not an nsXULWindow. Persist it.
+    // not an AppWindow. Persist it.
    if (aElement->OwnerDoc()->GetInProcessParentDocument()) {
      return true;
    }
    // The following attributes of xul:window should be handled in
-    // nsXULWindow::SavePersistentAttributes instead of here.
+    // AppWindow::SavePersistentAttributes instead of here.
    if (aAttribute == nsGkAtoms::screenX || aAttribute == nsGkAtoms::screenY ||
        aAttribute == nsGkAtoms::width || aAttribute == nsGkAtoms::height ||
        aAttribute == nsGkAtoms::sizemode) {
@ -66,7 +66,7 @@ void XULPersist::AttributeChanged(dom::Element* aElement, int32_t aNameSpaceID,
  //
  // XXX Namespace handling broken :-(
  nsAutoString persist;
-  // Persistence of attributes of xul:window is handled in nsXULWindow.
+  // Persistence of attributes of xul:window is handled in AppWindow.
  if (aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::persist, persist) &&
      ShouldPersistAttribute(aElement, aAttribute) && !persist.IsEmpty() &&
      // XXXldb This should check that it's a token, not just a substring.
@ -135,10 +135,10 @@ void XULPersist::Persist(Element* aElement, int32_t aNameSpaceID,
    return;
  }

-  // Persisting attributes to top level windows is handled by nsXULWindow.
+  // Persisting attributes to top level windows is handled by AppWindow.
  if (IsRootElement(aElement)) {
-    if (nsCOMPtr<nsIXULWindow> win =
-            mDocument->GetXULWindowIfToplevelChrome()) {
+    if (nsCOMPtr<nsIAppWindow> win =
+            mDocument->GetAppWindowIfToplevelChrome()) {
      return;
    }
  }
@ -300,10 +300,10 @@ nsresult XULPersist::ApplyPersistentAttributesToElements(
      }

      // Applying persistent attributes to top level windows is handled
-      // by nsXULWindow.
+      // by AppWindow.
      if (IsRootElement(element)) {
-        if (nsCOMPtr<nsIXULWindow> win =
-                mDocument->GetXULWindowIfToplevelChrome()) {
+        if (nsCOMPtr<nsIAppWindow> win =
+                mDocument->GetAppWindowIfToplevelChrome()) {
          continue;
        }
      }
--- a/testing/talos/talos/tests/devtools/addon/api.js
+++ b/testing/talos/talos/tests/devtools/addon/api.js
@ -13,7 +13,7 @@ this.damp = class extends ExtensionAPI {
      damp: {
        startTest() {
          let { rootURI } = context.extension;
-          let window = context.xulWindow;
+          let window = context.appWindow;
          if (!("Damp" in window)) {
            let script = rootURI.resolve("content/damp.js");
            Services.scriptloader.loadSubScript(script, window);
--- a/testing/talos/talos/tests/twinopen/api.js
+++ b/testing/talos/talos/tests/twinopen/api.js
@ -55,7 +55,7 @@ async function startTest(context) {
  Cu.forceGC();
  Cu.forceCC();
  Cu.forceShrinkingGC();
-  let win = context.xulWindow;
+  let win = context.appWindow;
  await openDelay(win);
  let mozAfterPaint = waitForBrowserPaint();

--- a/toolkit/components/browser/nsWebBrowser.cpp
+++ b/toolkit/components/browser/nsWebBrowser.cpp
@ -1079,7 +1079,7 @@ nsWebBrowser::SetParentNativeWindow(nativeWindow aParentNativeWindow) {

 NS_IMETHODIMP
 nsWebBrowser::GetNativeHandle(nsAString& aNativeHandle) {
-  // the nativeHandle should be accessed from nsIXULWindow
+  // the nativeHandle should be accessed from nsIAppWindow
  return NS_ERROR_NOT_IMPLEMENTED;
 }

--- a/toolkit/components/extensions/ExtensionParent.jsm
+++ b/toolkit/components/extensions/ExtensionParent.jsm
@ -808,14 +808,14 @@ class ExtensionPageContextParent extends ProxyContextParent {
  }

  // The window that contains this context. This may change due to moving tabs.
-  get xulWindow() {
+  get appWindow() {
    let win = this.xulBrowser.ownerGlobal;
    return win.docShell.rootTreeItem.domWindow;
  }

  get currentWindow() {
    if (this.viewType !== "background") {
-      return this.xulWindow;
+      return this.appWindow;
    }
  }

--- a/toolkit/components/extensions/parent/ext-tabs-base.js
+++ b/toolkit/components/extensions/parent/ext-tabs-base.js
@ -843,14 +843,14 @@ class WindowBase {
  }

  /**
-   * @property {nsIXULWindow} xulWindow
-   *        The nsIXULWindow object for this browser window.
+   * @property {nsIAppWindow} appWindow
+   *        The nsIAppWindow object for this browser window.
   *        @readonly
   */
-  get xulWindow() {
+  get appWindow() {
    return this.window.docShell.treeOwner
      .QueryInterface(Ci.nsIInterfaceRequestor)
-      .getInterface(Ci.nsIXULWindow);
+      .getInterface(Ci.nsIAppWindow);
  }

  /**
@ -876,7 +876,7 @@ class WindowBase {
   *        @readonly
   */
  get type() {
-    let { chromeFlags } = this.xulWindow;
+    let { chromeFlags } = this.appWindow;

    if (chromeFlags & Ci.nsIWebBrowserChrome.CHROME_OPENAS_DIALOG) {
      return "popup";
--- a/toolkit/components/printingui/nsPrintProgress.cpp
+++ b/toolkit/components/printingui/nsPrintProgress.cpp
@ -11,7 +11,7 @@
 #include "nsIDocShell.h"
 #include "nsIDocShellTreeOwner.h"
 #include "nsIInterfaceRequestorUtils.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsXPCOM.h"
 #include "nsISupportsPrimitives.h"
 #include "nsIComponentManager.h"
@ -75,8 +75,8 @@ NS_IMETHODIMP nsPrintProgress::OpenProgressDialog(
    nsCOMPtr<nsIDocShellTreeOwner> owner;
    docShell->GetTreeOwner(getter_AddRefs(owner));

-    nsCOMPtr<nsIXULWindow> ownerXULWindow = do_GetInterface(owner);
-    nsCOMPtr<mozIDOMWindowProxy> ownerWindow = do_GetInterface(ownerXULWindow);
+    nsCOMPtr<nsIAppWindow> ownerAppWindow = do_GetInterface(owner);
+    nsCOMPtr<mozIDOMWindowProxy> ownerWindow = do_GetInterface(ownerAppWindow);
    NS_ENSURE_STATE(ownerWindow);

    nsCOMPtr<nsPIDOMWindowOuter> piOwnerWindow =
--- a/toolkit/components/prompts/test/chromeScript.js
+++ b/toolkit/components/prompts/test/chromeScript.js
@ -138,7 +138,7 @@ function getPromptState(ui) {
    // We can't just check window.opener because that'll be
    // a content window, which therefore isn't exposed (it'll lie and
    // be null).
-    let flags = treeOwner.getInterface(Ci.nsIXULWindow).chromeFlags;
+    let flags = treeOwner.getInterface(Ci.nsIAppWindow).chromeFlags;
    state.chrome = (flags & Ci.nsIWebBrowserChrome.CHROME_OPENAS_CHROME) != 0;
    state.dialog = (flags & Ci.nsIWebBrowserChrome.CHROME_OPENAS_DIALOG) != 0;
    state.chromeDependent =
--- a/toolkit/components/sessionstore/SessionStoreListener.cpp
+++ b/toolkit/components/sessionstore/SessionStoreListener.cpp
@ -17,7 +17,7 @@
 #include "nsIPrefService.h"
 #include "nsIPrefBranch.h"
 #include "nsITimer.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIWebProgress.h"
 #include "nsPresContext.h"
 #include "nsPrintfCString.h"
@ -666,7 +666,7 @@ bool TabListener::UpdateSessionStore(uint32_t aFlushId, bool aIsFinal) {
  if (!treeOwner) {
    return false;
  }
-  nsCOMPtr<nsIXULWindow> window(do_GetInterface(treeOwner));
+  nsCOMPtr<nsIAppWindow> window(do_GetInterface(treeOwner));
  if (!window) {
    return false;
  }
--- a/toolkit/components/startup/nsAppStartup.cpp
+++ b/toolkit/components/startup/nsAppStartup.cpp
@ -21,7 +21,7 @@
 #include "nsIWindowMediator.h"
 #include "nsIWindowWatcher.h"
 #include "nsIXULRuntime.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsNativeCharsetUtils.h"
 #include "nsThreadUtils.h"
 #include "nsAutoPtr.h"
@ -318,7 +318,7 @@ nsAppStartup::Quit(uint32_t aMode) {

      bool usefulHiddenWindow;
      appShell->GetApplicationProvidedHiddenWindow(&usefulHiddenWindow);
-      nsCOMPtr<nsIXULWindow> hiddenWindow;
+      nsCOMPtr<nsIAppWindow> hiddenWindow;
      appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
      // If the remaining windows are useful, we won't quit:
      if (!hiddenWindow || usefulHiddenWindow) {
@ -597,16 +597,16 @@ nsAppStartup::CreateChromeWindow(nsIWebBrowserChrome* aParent,
    return NS_ERROR_FAILURE;
  }

-  nsCOMPtr<nsIXULWindow> newWindow;
+  nsCOMPtr<nsIAppWindow> newWindow;

  if (aParent) {
-    nsCOMPtr<nsIXULWindow> xulParent(do_GetInterface(aParent));
-    NS_ASSERTION(xulParent,
-                 "window created using non-XUL parent. that's unexpected, but "
+    nsCOMPtr<nsIAppWindow> appParent(do_GetInterface(aParent));
+    NS_ASSERTION(appParent,
+                 "window created using non-app parent. that's unexpected, but "
                 "may work.");

-    if (xulParent)
-      xulParent->CreateNewWindow(aChromeFlags, aOpeningTab, aOpener,
+    if (appParent)
+      appParent->CreateNewWindow(aChromeFlags, aOpeningTab, aOpener,
                                 aNextRemoteTabId, getter_AddRefs(newWindow));
    // And if it fails, don't try again without a parent. It could fail
    // intentionally (bug 115969).
--- a/toolkit/components/windowwatcher/nsWindowWatcher.cpp
+++ b/toolkit/components/windowwatcher/nsWindowWatcher.cpp
@ -71,7 +71,7 @@
 #include "mozilla/dom/BrowserHost.h"
 #include "mozilla/dom/DocGroup.h"
 #include "mozilla/dom/TabGroup.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIXULBrowserWindow.h"
 #include "nsGlobalWindow.h"
 #include "ReferrerInfo.h"
@ -911,17 +911,17 @@ nsresult nsWindowWatcher::OpenWindowInternal(
      }

      if (newChrome) {
-        nsCOMPtr<nsIXULWindow> xulWin = do_GetInterface(newChrome);
-        if (xulWin) {
+        nsCOMPtr<nsIAppWindow> appWin = do_GetInterface(newChrome);
+        if (appWin) {
          nsCOMPtr<nsIXULBrowserWindow> xulBrowserWin;
-          xulWin->GetXULBrowserWindow(getter_AddRefs(xulBrowserWin));
+          appWin->GetXULBrowserWindow(getter_AddRefs(xulBrowserWin));
          if (xulBrowserWin) {
            nsPIDOMWindowOuter* openerWindow =
                aForceNoOpener ? nullptr : parentWindow.get();
            xulBrowserWin->ForceInitialBrowserNonRemote(openerWindow);
          }
        }
-        /* It might be a chrome nsXULWindow, in which case it won't have
+        /* It might be a chrome AppWindow, in which case it won't have
            an nsIDOMWindow (primary content shell). But in that case, it'll
            be able to hand over an nsIDocShellTreeItem directly. */
        nsCOMPtr<nsPIDOMWindowOuter> newWindow(do_GetInterface(newChrome));
@ -2372,9 +2372,9 @@ void nsWindowWatcher::SizeOpenedWindow(nsIDocShellTreeOwner* aTreeOwner,
  }

  if (aIsCallerChrome) {
-    nsCOMPtr<nsIXULWindow> xulWin = do_GetInterface(treeOwnerAsWin);
-    if (xulWin && aSizeSpec.mLockAspectRatio) {
-      xulWin->LockAspectRatio(true);
+    nsCOMPtr<nsIAppWindow> appWin = do_GetInterface(treeOwnerAsWin);
+    if (appWin && aSizeSpec.mLockAspectRatio) {
+      appWin->LockAspectRatio(true);
    }
  }

--- a/toolkit/components/windowwatcher/test/browser_new_content_window_chromeflags.js
+++ b/toolkit/components/windowwatcher/test/browser_new_content_window_chromeflags.js
@ -152,7 +152,7 @@ registerCleanupFunction(() => {
 function getParentChromeFlags(win) {
  return win.docShell.treeOwner
    .QueryInterface(Ci.nsIInterfaceRequestor)
-    .getInterface(Ci.nsIXULWindow).chromeFlags;
+    .getInterface(Ci.nsIAppWindow).chromeFlags;
 }

 /**
--- a/toolkit/components/windowwatcher/test/browser_new_remote_window_flags.js
+++ b/toolkit/components/windowwatcher/test/browser_new_remote_window_flags.js
@ -20,7 +20,7 @@ function assertFlags(win) {
  let loadContext = docShell.QueryInterface(Ci.nsILoadContext);
  let chromeFlags = docShell.treeOwner
    .QueryInterface(Ci.nsIInterfaceRequestor)
-    .getInterface(Ci.nsIXULWindow).chromeFlags;
+    .getInterface(Ci.nsIAppWindow).chromeFlags;
  Assert.ok(
    loadContext.useRemoteTabs,
    "Should be using remote tabs on the load context"
--- a/toolkit/components/windowwatcher/test/test_alwaysOnTop_windows.html
+++ b/toolkit/components/windowwatcher/test/test_alwaysOnTop_windows.html
@ -20,7 +20,7 @@ Tests the alwaysOnTop window feature for the Windows OS.
    let docShell = win.docShell;
    let chromeFlags = docShell.treeOwner
                              .QueryInterface(Ci.nsIInterfaceRequestor)
-                              .getInterface(Ci.nsIXULWindow)
+                              .getInterface(Ci.nsIAppWindow)
                              .chromeFlags;
    let hasFlag = !!(chromeFlags & Ci.nsIWebBrowserChrome.CHROME_ALWAYS_ON_TOP);
    is(hasFlag, expected, "Window should have CHROME_ALWAYS_ON_TOP flag.");
--- a/toolkit/components/windowwatcher/test/test_modal_windows.html
+++ b/toolkit/components/windowwatcher/test/test_modal_windows.html
@ -20,7 +20,7 @@ that is opened reports itself as being modal.
    BrowserTestUtils.domWindowOpened().then((win) => {
      let treeOwner = win.docShell.treeOwner;
      let chromeFlags = treeOwner.QueryInterface(Ci.nsIInterfaceRequestor)
-                                 .getInterface(Ci.nsIXULWindow)
+                                 .getInterface(Ci.nsIAppWindow)
                                 .chromeFlags;
      ok(chromeFlags & Ci.nsIWebBrowserChrome.CHROME_MODAL,
         "Should have the modal chrome flag");
--- a/toolkit/components/xulstore/new/XULStore.jsm
+++ b/toolkit/components/xulstore/new/XULStore.jsm
@ -56,7 +56,7 @@ const XULStore = {
    const value = node.getAttribute(attr);

    if (node.localName == "window") {
-      log("Persisting attributes to windows is handled by nsXULWindow.");
+      log("Persisting attributes to windows is handled by AppWindow.");
      return;
    }

--- a/toolkit/components/xulstore/old/XULStore.jsm
+++ b/toolkit/components/xulstore/old/XULStore.jsm
@ -142,7 +142,7 @@ XULStore.prototype = {
    const value = node.getAttribute(attr);

    if (node.localName == "window") {
-      this.log("Persisting attributes to windows is handled by nsXULWindow.");
+      this.log("Persisting attributes to windows is handled by AppWindow.");
      return;
    }

--- a/toolkit/content/tests/chrome/findbar_window.xul
+++ b/toolkit/content/tests/chrome/findbar_window.xul
@ -66,7 +66,7 @@
        window.docShell
              .treeOwner
              .QueryInterface(Ci.nsIInterfaceRequestor)
-              .getInterface(Ci.nsIXULWindow)
+              .getInterface(Ci.nsIAppWindow)
              .XULBrowserWindow = gXULBrowserWindow;

        gFindBar = document.getElementById("FindToolbar");
--- a/toolkit/content/widgets/findbar.js
+++ b/toolkit/content/widgets/findbar.js
@ -746,7 +746,7 @@
        try {
          this._xulBrowserWindow = window.docShell.treeOwner
            .QueryInterface(Ci.nsIInterfaceRequestor)
-            .getInterface(Ci.nsIXULWindow).XULBrowserWindow;
+            .getInterface(Ci.nsIAppWindow).XULBrowserWindow;
        } catch (ex) {}
        if (!this._xulBrowserWindow) {
          return false;
--- a/toolkit/xre/nsINativeAppSupport.idl
+++ b/toolkit/xre/nsINativeAppSupport.idl
@ -44,8 +44,6 @@
 *                         "soft" shutdown, passwords are flushed.
 */

-interface nsIXULWindow;
-
 [scriptable, uuid(5fdf8480-1f98-11d4-8077-00600811a9c3)]
 interface nsINativeAppSupport : nsISupports {
    // Startup/shutdown.
--- a/toolkit/xre/nsNativeAppSupportCocoa.mm
+++ b/toolkit/xre/nsNativeAppSupportCocoa.mm
@ -280,7 +280,7 @@ nsNativeAppSupportCocoa::ReOpen() {
    return NS_ERROR_FAILURE;
  } else {
    nsCOMPtr<nsISimpleEnumerator> windowList;
-    wm->GetXULWindowEnumerator(nullptr, getter_AddRefs(windowList));
+    wm->GetAppWindowEnumerator(nullptr, getter_AddRefs(windowList));
    bool more;
    windowList->HasMoreElements(&more);
    while (more) {
--- a/widget/android/nsWindow.cpp
+++ b/widget/android/nsWindow.cpp
@ -50,7 +50,7 @@ using mozilla::dom::ContentParent;
 #include "nsISupportsPrimitives.h"
 #include "nsIWidgetListener.h"
 #include "nsIWindowWatcher.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"

 #include "nsAppShell.h"
 #include "nsFocusManager.h"
@ -1315,11 +1315,11 @@ void nsWindow::GeckoViewSupport::Open(
                                      aInitData);

  if (window->mWidgetListener) {
-    nsCOMPtr<nsIXULWindow> xulWindow(window->mWidgetListener->GetXULWindow());
-    if (xulWindow) {
-      // Our window is not intrinsically sized, so tell nsXULWindow to
+    nsCOMPtr<nsIAppWindow> appWindow(window->mWidgetListener->GetAppWindow());
+    if (appWindow) {
+      // Our window is not intrinsically sized, so tell AppWindow to
      // not set a size for us.
-      xulWindow->SetIntrinsicallySized(false);
+      appWindow->SetIntrinsicallySized(false);
    }
  }
 }
--- a/widget/cocoa/nsChildView.h
+++ b/widget/cocoa/nsChildView.h
@ -523,7 +523,7 @@ class nsChildView final : public nsBaseWidget {

  NSView<mozView>* GetEditorView();

-  nsCocoaWindow* GetXULWindowWidget() const;
+  nsCocoaWindow* GetAppWindowWidget() const;

  virtual void ReparentNativeWidget(nsIWidget* aNewParent) override;

--- a/widget/cocoa/nsChildView.mm
+++ b/widget/cocoa/nsChildView.mm
@ -492,7 +492,7 @@ void nsChildView::TearDownView() {
  NS_OBJC_END_TRY_ABORT_BLOCK;
 }

-nsCocoaWindow* nsChildView::GetXULWindowWidget() const {
+nsCocoaWindow* nsChildView::GetAppWindowWidget() const {
  id windowDelegate = [[mView window] delegate];
  if (windowDelegate && [windowDelegate isKindOfClass:[WindowDelegate class]]) {
    return [(WindowDelegate*)windowDelegate geckoWidget];
@ -594,7 +594,7 @@ void* nsChildView::GetNativeData(uint32_t aDataType) {
 nsTransparencyMode nsChildView::GetTransparencyMode() {
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_RETURN;

-  nsCocoaWindow* windowWidget = GetXULWindowWidget();
+  nsCocoaWindow* windowWidget = GetAppWindowWidget();
  return windowWidget ? windowWidget->GetTransparencyMode() : eTransparencyOpaque;

  NS_OBJC_END_TRY_ABORT_BLOCK_RETURN(eTransparencyOpaque);
@ -605,7 +605,7 @@ nsTransparencyMode nsChildView::GetTransparencyMode() {
 void nsChildView::SetTransparencyMode(nsTransparencyMode aMode) {
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

-  nsCocoaWindow* windowWidget = GetXULWindowWidget();
+  nsCocoaWindow* windowWidget = GetAppWindowWidget();
  if (windowWidget) {
    windowWidget->SetTransparencyMode(aMode);
  }
@ -616,7 +616,7 @@ void nsChildView::SetTransparencyMode(nsTransparencyMode aMode) {
 }

 void nsChildView::SuppressAnimation(bool aSuppress) {
-  GetXULWindowWidget()->SuppressAnimation(aSuppress);
+  GetAppWindowWidget()->SuppressAnimation(aSuppress);
 }

 bool nsChildView::IsVisible() const {
@ -626,7 +626,7 @@ bool nsChildView::IsVisible() const {
    return mVisible;
  }

-  if (!GetXULWindowWidget()->IsVisible()) {
+  if (!GetAppWindowWidget()->IsVisible()) {
    return false;
  }

@ -833,7 +833,7 @@ void nsChildView::BackingScaleFactorChanged() {
    mNativeLayerRoot->SetBackingScale(mBackingScaleFactor);
  }

-  if (mWidgetListener && !mWidgetListener->GetXULWindow()) {
+  if (mWidgetListener && !mWidgetListener->GetAppWindow()) {
    if (PresShell* presShell = mWidgetListener->GetPresShell()) {
      presShell->BackingScaleFactorChanged();
    }
@ -1167,7 +1167,7 @@ static NSMenuItem* NativeMenuItemWithLocation(NSMenu* menubar, NSString* locatio

 bool nsChildView::SendEventToNativeMenuSystem(NSEvent* aEvent) {
  bool handled = false;
-  nsCocoaWindow* widget = GetXULWindowWidget();
+  nsCocoaWindow* widget = GetAppWindowWidget();
  if (widget) {
    nsMenuBarX* mb = widget->GetMenuBar();
    if (mb) {
@ -1232,7 +1232,7 @@ nsresult nsChildView::ActivateNativeMenuItemAt(const nsAString& indexString) {
 nsresult nsChildView::ForceUpdateNativeMenuAt(const nsAString& indexString) {
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;

-  nsCocoaWindow* widget = GetXULWindowWidget();
+  nsCocoaWindow* widget = GetAppWindowWidget();
  if (widget) {
    nsMenuBarX* mb = widget->GetMenuBar();
    if (mb) {
@ -1912,7 +1912,7 @@ void nsChildView::PrepareWindowEffects() {
    mIsCoveringTitlebar = [mView isCoveringTitlebar];
    NSInteger styleMask = [[mView window] styleMask];
    bool wasFullscreen = mIsFullscreen;
-    nsCocoaWindow* windowWidget = GetXULWindowWidget();
+    nsCocoaWindow* windowWidget = GetAppWindowWidget();
    mIsFullscreen =
        (styleMask & NSFullScreenWindowMask) || (windowWidget && windowWidget->InFullScreenMode());

@ -3438,7 +3438,7 @@ NSEvent* gLastDragMouseDownEvent = nil;  // [strong]
 }

 - (void)viewWillStartLiveResize {
-  nsCocoaWindow* windowWidget = mGeckoChild ? mGeckoChild->GetXULWindowWidget() : nullptr;
+  nsCocoaWindow* windowWidget = mGeckoChild ? mGeckoChild->GetAppWindowWidget() : nullptr;
  if (windowWidget) {
    windowWidget->NotifyLiveResizeStarted();
  }
@ -3451,7 +3451,7 @@ NSEvent* gLastDragMouseDownEvent = nil;  // [strong]
  // is null here, that might be problematic because we might get stuck with
  // a content process that has the displayport suppressed. If that scenario
  // arises (I'm not sure that it does) we will need to handle it gracefully.
-  nsCocoaWindow* windowWidget = mGeckoChild ? mGeckoChild->GetXULWindowWidget() : nullptr;
+  nsCocoaWindow* windowWidget = mGeckoChild ? mGeckoChild->GetAppWindowWidget() : nullptr;
  if (windowWidget) {
    windowWidget->NotifyLiveResizeStopped();
  }
--- a/widget/cocoa/nsCocoaUtils.mm
+++ b/widget/cocoa/nsCocoaUtils.mm
@ -22,7 +22,7 @@
 #include "nsIAppShellService.h"
 #include "nsIOSPermissionRequest.h"
 #include "nsIRunnable.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIBaseWindow.h"
 #include "nsIServiceManager.h"
 #include "nsMenuUtilsX.h"
@ -274,7 +274,7 @@ nsIWidget* nsCocoaUtils::GetHiddenWindowWidget() {
    return nullptr;
  }

-  nsCOMPtr<nsIXULWindow> hiddenWindow;
+  nsCOMPtr<nsIAppWindow> hiddenWindow;
  appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
  if (!hiddenWindow) {
    // Don't warn, this happens during shutdown, bug 358607.
@ -284,7 +284,7 @@ nsIWidget* nsCocoaUtils::GetHiddenWindowWidget() {
  nsCOMPtr<nsIBaseWindow> baseHiddenWindow;
  baseHiddenWindow = do_GetInterface(hiddenWindow);
  if (!baseHiddenWindow) {
-    NS_WARNING("Couldn't get nsIBaseWindow from hidden window (nsIXULWindow)");
+    NS_WARNING("Couldn't get nsIBaseWindow from hidden window (nsIAppWindow)");
    return nullptr;
  }

--- a/widget/cocoa/nsCocoaWindow.mm
+++ b/widget/cocoa/nsCocoaWindow.mm
@ -19,7 +19,7 @@
 #include "nsIAppShellService.h"
 #include "nsIBaseWindow.h"
 #include "nsIInterfaceRequestorUtils.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsToolkit.h"
 #include "nsTouchBarNativeAPIDefines.h"
 #include "nsPIDOMWindow.h"
@ -665,7 +665,7 @@ void nsCocoaWindow::SetModal(bool aState) {
    // appears over behave as they should.  We can't rely on native methods to
    // do this, for the following reason:  The OS runs modal non-sheet windows
    // in an event loop (using [NSApplication runModalForWindow:] or similar
-    // methods) that's incompatible with the modal event loop in nsXULWindow::
+    // methods) that's incompatible with the modal event loop in AppWindow::
    // ShowModal() (each of these event loops is "exclusive", and can't run at
    // the same time as other (similar) event loops).
    if (mWindowType != eWindowType_sheet) {
@ -1655,7 +1655,7 @@ void nsCocoaWindow::BackingScaleFactorChanged() {

  mBackingScaleFactor = newScale;

-  if (!mWidgetListener || mWidgetListener->GetXULWindow()) {
+  if (!mWidgetListener || mWidgetListener->GetAppWindow()) {
    return;
  }

--- a/widget/nsBaseWidget.cpp
+++ b/widget/nsBaseWidget.cpp
@ -34,7 +34,7 @@
 #include "ClientLayerManager.h"
 #include "mozilla/layers/Compositor.h"
 #include "nsIXULRuntime.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIBaseWindow.h"
 #include "nsXULPopupManager.h"
 #include "nsIWidgetListener.h"
@ -1642,10 +1642,10 @@ nsIRollupListener* nsBaseWidget::GetActiveRollupListener() {
 void nsBaseWidget::NotifyWindowDestroyed() {
  if (!mWidgetListener) return;

-  nsCOMPtr<nsIXULWindow> window = mWidgetListener->GetXULWindow();
-  nsCOMPtr<nsIBaseWindow> xulWindow(do_QueryInterface(window));
-  if (xulWindow) {
-    xulWindow->Destroy();
+  nsCOMPtr<nsIAppWindow> window = mWidgetListener->GetAppWindow();
+  nsCOMPtr<nsIBaseWindow> appWindow(do_QueryInterface(window));
+  if (appWindow) {
+    appWindow->Destroy();
  }
 }

@ -2028,11 +2028,11 @@ void nsBaseWidget::NotifyLiveResizeStarted() {
  if (!mWidgetListener) {
    return;
  }
-  nsCOMPtr<nsIXULWindow> xulWindow = mWidgetListener->GetXULWindow();
-  if (!xulWindow) {
+  nsCOMPtr<nsIAppWindow> appWindow = mWidgetListener->GetAppWindow();
+  if (!appWindow) {
    return;
  }
-  mLiveResizeListeners = xulWindow->GetLiveResizeListeners();
+  mLiveResizeListeners = appWindow->GetLiveResizeListeners();
  for (uint32_t i = 0; i < mLiveResizeListeners.Length(); i++) {
    mLiveResizeListeners[i]->LiveResizeStarted();
  }
--- a/widget/nsIWidgetListener.cpp
+++ b/widget/nsIWidgetListener.cpp
@ -8,14 +8,14 @@
 #include "nsRegion.h"
 #include "nsView.h"
 #include "nsIWidget.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"

 #include "mozilla/BasicEvents.h"
 #include "mozilla/PresShell.h"

 using namespace mozilla;

-nsIXULWindow* nsIWidgetListener::GetXULWindow() { return nullptr; }
+nsIAppWindow* nsIWidgetListener::GetAppWindow() { return nullptr; }

 nsView* nsIWidgetListener::GetView() { return nullptr; }

--- a/widget/nsIWidgetListener.h
+++ b/widget/nsIWidgetListener.h
@ -16,7 +16,7 @@

 class nsView;
 class nsIWidget;
-class nsIXULWindow;
+class nsIAppWindow;

 namespace mozilla {
 class PresShell;
@ -45,11 +45,11 @@ enum nsWindowZ {
 class nsIWidgetListener {
 public:
  /**
-   * If this listener is for an nsIXULWindow, return it. If this is null, then
+   * If this listener is for an nsIAppWindow, return it. If this is null, then
   * this is likely a listener for a view, which can be determined using
   * GetView. If both methods return null, this will be an nsWebBrowser.
   */
-  virtual nsIXULWindow* GetXULWindow();
+  virtual nsIAppWindow* GetAppWindow();

  /**
   * If this listener is for an nsView, return it.
--- a/widget/tests/TestAppShellSteadyState.cpp
+++ b/widget/tests/TestAppShellSteadyState.cpp
@ -16,7 +16,7 @@
 #include "nsIRunnable.h"
 #include "nsIURI.h"
 #include "nsIWebBrowserChrome.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"

 #include "nsAppShellCID.h"
 #include "nsIInterfaceRequestorUtils.h"
@ -361,14 +361,14 @@ bool Test4Internal(nsIAppShell* aAppShell) {

  uint32_t flags = nsIWebBrowserChrome::CHROME_DEFAULT;

-  nsCOMPtr<nsIXULWindow> xulWindow;
+  nsCOMPtr<nsIAppWindow> appWindow;
  if (NS_FAILED(appService->CreateTopLevelWindow(
-          nullptr, uri, flags, 100, 100, nullptr, getter_AddRefs(xulWindow)))) {
+          nullptr, uri, flags, 100, 100, nullptr, getter_AddRefs(appWindow)))) {
    fail("Failed to create new window");
    return false;
  }

-  nsCOMPtr<nsIDOMWindow> window = do_GetInterface(xulWindow);
+  nsCOMPtr<nsIDOMWindow> window = do_GetInterface(appWindow);
  if (!window) {
    fail("Can't get dom window!");
    return false;
--- a/widget/windows/WidgetTraceEvent.cpp
+++ b/widget/windows/WidgetTraceEvent.cpp
@ -20,7 +20,7 @@
 #include "nsIDocShell.h"
 #include "nsISupportsImpl.h"
 #include "nsIWidget.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsServiceManagerUtils.h"
 #include "nsThreadUtils.h"
 #include "nsWindowDefs.h"
@ -42,7 +42,7 @@ class HWNDGetter : public mozilla::Runnable {
    // Jump through some hoops to locate the hidden window.
    nsCOMPtr<nsIAppShellService> appShell(
        do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
-    nsCOMPtr<nsIXULWindow> hiddenWindow;
+    nsCOMPtr<nsIAppWindow> hiddenWindow;

    nsresult rv = appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
    if (NS_FAILED(rv)) {
--- a/widget/windows/WindowsUIUtils.cpp
+++ b/widget/windows/WindowsUIUtils.cpp
@ -16,7 +16,6 @@
 #include "nsIDocShell.h"
 #include "nsIAppShellService.h"
 #include "nsAppShellCID.h"
-#include "nsIXULWindow.h"
 #include "mozilla/Services.h"
 #include "mozilla/WidgetUtils.h"
 #include "mozilla/WindowsVersion.h"
--- a/xpfe/appshell/nsXULWindow.cpp
+++ b/xpfe/appshell/nsXULWindow.cpp
--- a/xpfe/appshell/nsXULWindow.h
+++ b/xpfe/appshell/nsXULWindow.h
@ -4,8 +4,8 @@
 * 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 nsXULWindow_h__
-#define nsXULWindow_h__
+#ifndef mozilla_AppWindow_h__
+#define mozilla_AppWindow_h__

 // Local Includes
 #include "nsChromeTreeOwner.h"
@ -27,7 +27,7 @@
 #include "nsIDocShellTreeItem.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "nsIPrompt.h"
 #include "nsIAuthPrompt.h"
 #include "nsIXULBrowserWindow.h"
@ -52,12 +52,12 @@ struct nsWidgetInitData;

 namespace mozilla {
 class PresShell;
-class nsXULWindowTimerCallback;
+class AppWindowTimerCallback;
 }  // namespace mozilla

-// nsXULWindow
+// AppWindow

-#define NS_XULWINDOW_IMPL_CID                        \
+#define NS_APPWINDOW_IMPL_CID                        \
  { /* 8eaec2f3-ed02-4be2-8e0f-342798477298 */       \
    0x8eaec2f3, 0xed02, 0x4be2, {                    \
      0x8e, 0x0f, 0x34, 0x27, 0x98, 0x47, 0x72, 0x98 \
@ -66,25 +66,27 @@ class nsXULWindowTimerCallback;

 class nsContentShellInfo;

-class nsXULWindow final : public nsIBaseWindow,
-                          public nsIInterfaceRequestor,
-                          public nsIXULWindow,
-                          public nsSupportsWeakReference,
-                          public nsIWebProgressListener {
-  friend class nsChromeTreeOwner;
-  friend class nsContentTreeOwner;
+namespace mozilla {
+
+class AppWindow final : public nsIBaseWindow,
+                        public nsIInterfaceRequestor,
+                        public nsIAppWindow,
+                        public nsSupportsWeakReference,
+                        public nsIWebProgressListener {
+  friend class ::nsChromeTreeOwner;
+  friend class ::nsContentTreeOwner;

 public:
  // The implementation of non-refcounted nsIWidgetListener, which would hold a
-  // strong reference on stack before calling nsXULWindow's
+  // strong reference on stack before calling AppWindow's
  // MOZ_CAN_RUN_SCRIPT methods.
  class WidgetListenerDelegate : public nsIWidgetListener {
   public:
-    explicit WidgetListenerDelegate(nsXULWindow* aXULWindow)
-        : mXULWindow(aXULWindow) {}
+    explicit WidgetListenerDelegate(AppWindow* aAppWindow)
+        : mAppWindow(aAppWindow) {}

    MOZ_CAN_RUN_SCRIPT_BOUNDARY
-    virtual nsIXULWindow* GetXULWindow() override;
+    virtual nsIAppWindow* GetAppWindow() override;
    MOZ_CAN_RUN_SCRIPT_BOUNDARY
    virtual mozilla::PresShell* GetPresShell() override;
    MOZ_CAN_RUN_SCRIPT_BOUNDARY
@ -116,26 +118,26 @@ class nsXULWindow final : public nsIBaseWindow,
    virtual void WindowDeactivated() override;

   private:
-    // The lifetime of WidgetListenerDelegate is bound to nsXULWindow so
+    // The lifetime of WidgetListenerDelegate is bound to AppWindow so
    // we just use a raw pointer here.
-    nsXULWindow* mXULWindow;
+    AppWindow* mAppWindow;
  };

  NS_DECL_THREADSAFE_ISUPPORTS

  NS_DECL_NSIINTERFACEREQUESTOR
-  NS_DECL_NSIXULWINDOW
+  NS_DECL_NSIAPPWINDOW
  NS_DECL_NSIBASEWINDOW

-  NS_DECLARE_STATIC_IID_ACCESSOR(NS_XULWINDOW_IMPL_CID)
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_APPWINDOW_IMPL_CID)

  void LockUntilChromeLoad() { mLockedUntilChromeLoad = true; }
  bool IsLocked() const { return mLockedUntilChromeLoad; }
  void IgnoreXULSizeMode(bool aEnable) { mIgnoreXULSizeMode = aEnable; }
  void WasRegistered() { mRegistered = true; }

-  // nsXULWindow methods...
-  nsresult Initialize(nsIXULWindow* aParent, nsIXULWindow* aOpener,
+  // AppWindow methods...
+  nsresult Initialize(nsIAppWindow* aParent, nsIAppWindow* aOpener,
                      nsIURI* aUrl, int32_t aInitialWidth,
                      int32_t aInitialHeight, bool aIsHiddenWindow,
                      nsIRemoteTab* aOpeningTab,
@ -148,7 +150,7 @@ class nsXULWindow final : public nsIBaseWindow,
  NS_DECL_NSIWEBPROGRESSLISTENER

  // nsIWidgetListener methods for WidgetListenerDelegate.
-  nsIXULWindow* GetXULWindow() { return this; }
+  nsIAppWindow* GetAppWindow() { return this; }
  mozilla::PresShell* GetPresShell();
  MOZ_CAN_RUN_SCRIPT
  bool WindowMoved(nsIWidget* aWidget, int32_t aX, int32_t aY);
@ -167,7 +169,7 @@ class nsXULWindow final : public nsIBaseWindow,
  MOZ_CAN_RUN_SCRIPT void WindowActivated();
  MOZ_CAN_RUN_SCRIPT void WindowDeactivated();

-  explicit nsXULWindow(uint32_t aChromeFlags);
+  explicit AppWindow(uint32_t aChromeFlags);

 protected:
  enum persistentAttributes {
@ -176,9 +178,9 @@ class nsXULWindow final : public nsIBaseWindow,
    PAD_SIZE = 0x4
  };

-  virtual ~nsXULWindow();
+  virtual ~AppWindow();

-  friend class mozilla::nsXULWindowTimerCallback;
+  friend class mozilla::AppWindowTimerCallback;

  bool ExecuteCloseHandler();
  void ConstrainToOpenerScreen(int32_t* aX, int32_t* aY);
@ -227,19 +229,19 @@ class nsXULWindow final : public nsIBaseWindow,
  NS_IMETHOD CreateNewChromeWindow(int32_t aChromeFlags,
                                   nsIRemoteTab* aOpeningTab,
                                   mozIDOMWindowProxy* aOpenerWindow,
-                                   nsIXULWindow** _retval);
+                                   nsIAppWindow** _retval);
  NS_IMETHOD CreateNewContentWindow(int32_t aChromeFlags,
                                    nsIRemoteTab* aOpeningTab,
                                    mozIDOMWindowProxy* aOpenerWindow,
                                    uint64_t aNextRemoteTabId,
-                                    nsIXULWindow** _retval);
+                                    nsIAppWindow** _retval);
  NS_IMETHOD GetHasPrimaryContent(bool* aResult);

  void EnableParent(bool aEnable);
  bool ConstrainToZLevel(bool aImmediate, nsWindowZ* aPlacement,
                         nsIWidget* aReqBelow, nsIWidget** aActualBelow);
  void PlaceWindowLayersBehind(uint32_t aLowLevel, uint32_t aHighLevel,
-                               nsIXULWindow* aBehind);
+                               nsIAppWindow* aBehind);
  void SetContentScrollbarVisibility(bool aVisible);
  bool GetContentScrollbarVisibility();
  void PersistentAttributesDirty(uint32_t aDirtyFlags);
@ -304,5 +306,8 @@ class nsXULWindow final : public nsIBaseWindow,
 #endif
 };

-NS_DEFINE_STATIC_IID_ACCESSOR(nsXULWindow, NS_XULWINDOW_IMPL_CID)
-#endif /* nsXULWindow_h__ */
+NS_DEFINE_STATIC_IID_ACCESSOR(AppWindow, NS_APPWINDOW_IMPL_CID)
+
+}  // namespace mozilla
+
+#endif /* mozilla_AppWindow_h__ */
--- a/xpfe/appshell/moz.build
+++ b/xpfe/appshell/moz.build
@ -11,11 +11,11 @@ MOCHITEST_CHROME_MANIFESTS += ['test/chrome.ini']

 XPIDL_SOURCES += [
    'nsIAppShellService.idl',
+    'nsIAppWindow.idl',
    'nsIWindowlessBrowser.idl',
    'nsIWindowMediator.idl',
    'nsIWindowMediatorListener.idl',
    'nsIXULBrowserWindow.idl',
-    'nsIXULWindow.idl',
 ]

 XPIDL_MODULE = 'appshell'
@ -26,12 +26,12 @@ EXPORTS += [
 ]

 UNIFIED_SOURCES += [
+    'AppWindow.cpp',
    'nsAppShellService.cpp',
    'nsAppShellWindowEnumerator.cpp',
    'nsChromeTreeOwner.cpp',
    'nsContentTreeOwner.cpp',
    'nsWindowMediator.cpp',
-    'nsXULWindow.cpp',
 ]

 XPCOM_MANIFESTS += [
--- a/xpfe/appshell/nsAppShellService.cpp
+++ b/xpfe/appshell/nsAppShellService.cpp
@ -17,7 +17,7 @@
 #include "nsIWindowWatcher.h"
 #include "nsPIWindowWatcher.h"
 #include "nsPIDOMWindow.h"
-#include "nsXULWindow.h"
+#include "AppWindow.h"

 #include "nsWidgetInitData.h"
 #include "nsWidgetsCID.h"
@ -133,7 +133,7 @@ nsAppShellService::CreateHiddenWindow() {
  rv = NS_NewURI(getter_AddRefs(url), hiddenWindowURL);
  NS_ENSURE_SUCCESS(rv, rv);

-  RefPtr<nsXULWindow> newWindow;
+  RefPtr<AppWindow> newWindow;
  rv =
      JustCreateTopWindow(nullptr, url, chromeMask, initialWidth, initialHeight,
                          true, nullptr, nullptr, getter_AddRefs(newWindow));
@ -166,16 +166,16 @@ nsAppShellService::DestroyHiddenWindow() {
 */
 NS_IMETHODIMP
 nsAppShellService::CreateTopLevelWindow(
-    nsIXULWindow* aParent, nsIURI* aUrl, uint32_t aChromeMask,
+    nsIAppWindow* aParent, nsIURI* aUrl, uint32_t aChromeMask,
    int32_t aInitialWidth, int32_t aInitialHeight, nsIRemoteTab* aOpeningTab,
-    mozIDOMWindowProxy* aOpenerWindow, nsIXULWindow** aResult)
+    mozIDOMWindowProxy* aOpenerWindow, nsIAppWindow** aResult)

 {
  nsresult rv;

  StartupTimeline::RecordOnce(StartupTimeline::CREATE_TOP_LEVEL_WINDOW);

-  RefPtr<nsXULWindow> newWindow;
+  RefPtr<AppWindow> newWindow;
  rv = JustCreateTopWindow(aParent, aUrl, aChromeMask, aInitialWidth,
                           aInitialHeight, false, aOpeningTab, aOpenerWindow,
                           getter_AddRefs(newWindow));
@ -184,7 +184,7 @@ nsAppShellService::CreateTopLevelWindow(
  if (NS_SUCCEEDED(rv)) {
    // the addref resulting from this is the owning addref for this window
    RegisterTopLevelWindow(*aResult);
-    nsCOMPtr<nsIXULWindow> parent;
+    nsCOMPtr<nsIAppWindow> parent;
    if (aChromeMask & nsIWebBrowserChrome::CHROME_DEPENDENT) parent = aParent;
    (*aResult)->SetZLevel(CalculateWindowZLevel(parent, aChromeMask));
  }
@ -485,15 +485,15 @@ nsAppShellService::CreateWindowlessBrowser(bool aIsChrome,
  return NS_OK;
 }

-uint32_t nsAppShellService::CalculateWindowZLevel(nsIXULWindow* aParent,
+uint32_t nsAppShellService::CalculateWindowZLevel(nsIAppWindow* aParent,
                                                  uint32_t aChromeMask) {
  uint32_t zLevel;

-  zLevel = nsIXULWindow::normalZ;
+  zLevel = nsIAppWindow::normalZ;
  if (aChromeMask & nsIWebBrowserChrome::CHROME_WINDOW_RAISED)
-    zLevel = nsIXULWindow::raisedZ;
+    zLevel = nsIAppWindow::raisedZ;
  else if (aChromeMask & nsIWebBrowserChrome::CHROME_WINDOW_LOWERED)
-    zLevel = nsIXULWindow::loweredZ;
+    zLevel = nsIAppWindow::loweredZ;

 #ifdef XP_MACOSX
  /* Platforms on which modal windows are always application-modal, not
@ -528,7 +528,7 @@ static bool CheckForFullscreenWindow() {
  if (!wm) return false;

  nsCOMPtr<nsISimpleEnumerator> windowList;
-  wm->GetXULWindowEnumerator(nullptr, getter_AddRefs(windowList));
+  wm->GetAppWindowEnumerator(nullptr, getter_AddRefs(windowList));
  if (!windowList) return false;

  for (;;) {
@ -555,17 +555,17 @@ static bool CheckForFullscreenWindow() {
 * Just do the window-making part of CreateTopLevelWindow
 */
 nsresult nsAppShellService::JustCreateTopWindow(
-    nsIXULWindow* aParent, nsIURI* aUrl, uint32_t aChromeMask,
+    nsIAppWindow* aParent, nsIURI* aUrl, uint32_t aChromeMask,
    int32_t aInitialWidth, int32_t aInitialHeight, bool aIsHiddenWindow,
    nsIRemoteTab* aOpeningTab, mozIDOMWindowProxy* aOpenerWindow,
-    nsXULWindow** aResult) {
+    AppWindow** aResult) {
  *aResult = nullptr;
  NS_ENSURE_STATE(!mXPCOMWillShutDown);

-  nsCOMPtr<nsIXULWindow> parent;
+  nsCOMPtr<nsIAppWindow> parent;
  if (aChromeMask & nsIWebBrowserChrome::CHROME_DEPENDENT) parent = aParent;

-  RefPtr<nsXULWindow> window = new nsXULWindow(aChromeMask);
+  RefPtr<AppWindow> window = new AppWindow(aChromeMask);

 #ifdef XP_WIN
  // If the parent is currently fullscreen, tell the child to ignore persisted
@ -737,7 +737,7 @@ nsresult nsAppShellService::JustCreateTopWindow(
 }

 NS_IMETHODIMP
-nsAppShellService::GetHiddenWindow(nsIXULWindow** aWindow) {
+nsAppShellService::GetHiddenWindow(nsIAppWindow** aWindow) {
  NS_ENSURE_ARG_POINTER(aWindow);

  EnsureHiddenWindow();
@ -784,7 +784,7 @@ nsAppShellService::GetApplicationProvidedHiddenWindow(bool* aAPHW) {
 * Register a new top level window (created elsewhere)
 */
 NS_IMETHODIMP
-nsAppShellService::RegisterTopLevelWindow(nsIXULWindow* aWindow) {
+nsAppShellService::RegisterTopLevelWindow(nsIAppWindow* aWindow) {
  NS_ENSURE_ARG_POINTER(aWindow);

  nsCOMPtr<nsIDocShell> docShell;
@ -816,15 +816,15 @@ nsAppShellService::RegisterTopLevelWindow(nsIXULWindow* aWindow) {

  if (obssvc) {
    obssvc->NotifyObservers(aWindow, "xul-window-registered", nullptr);
-    nsXULWindow* xulWindow = static_cast<nsXULWindow*>(aWindow);
-    xulWindow->WasRegistered();
+    AppWindow* appWindow = static_cast<AppWindow*>(aWindow);
+    appWindow->WasRegistered();
  }

  return NS_OK;
 }

 NS_IMETHODIMP
-nsAppShellService::UnregisterTopLevelWindow(nsIXULWindow* aWindow) {
+nsAppShellService::UnregisterTopLevelWindow(nsIAppWindow* aWindow) {
  if (mXPCOMShuttingDown) {
    /* return an error code in order to:
       - avoid doing anything with other member variables while we are in
--- a/xpfe/appshell/nsAppShellService.h
+++ b/xpfe/appshell/nsAppShellService.h
@ -10,7 +10,7 @@
 #include "nsIObserver.h"

 // Interfaces Needed
-#include "nsXULWindow.h"
+#include "AppWindow.h"
 #include "nsStringFwd.h"
 #include "nsAutoPtr.h"
 #include "nsIRemoteTab.h"
@ -37,15 +37,15 @@ class nsAppShellService final : public nsIAppShellService, public nsIObserver {

  void EnsureHiddenWindow();

-  nsresult JustCreateTopWindow(nsIXULWindow* aParent, nsIURI* aUrl,
+  nsresult JustCreateTopWindow(nsIAppWindow* aParent, nsIURI* aUrl,
                               uint32_t aChromeMask, int32_t aInitialWidth,
                               int32_t aInitialHeight, bool aIsHiddenWindow,
                               nsIRemoteTab* aOpeningTab,
                               mozIDOMWindowProxy* aOpenerWindow,
-                               nsXULWindow** aResult);
-  uint32_t CalculateWindowZLevel(nsIXULWindow* aParent, uint32_t aChromeMask);
+                               mozilla::AppWindow** aResult);
+  uint32_t CalculateWindowZLevel(nsIAppWindow* aParent, uint32_t aChromeMask);

-  RefPtr<nsXULWindow> mHiddenWindow;
+  RefPtr<mozilla::AppWindow> mHiddenWindow;
  bool mXPCOMWillShutDown;
  bool mXPCOMShuttingDown;
  uint16_t mModalWindowCount;
--- a/xpfe/appshell/nsAppShellWindowEnumerator.cpp
+++ b/xpfe/appshell/nsAppShellWindowEnumerator.cpp
@ -11,7 +11,7 @@
 #include "nsIFactory.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"
 #include "mozilla/dom/Element.h"

 #include "nsWindowMediator.h"
@ -23,9 +23,9 @@ using mozilla::dom::Element;
 // static helper functions
 //

-static void GetAttribute(nsIXULWindow* inWindow, const nsAString& inAttribute,
+static void GetAttribute(nsIAppWindow* inWindow, const nsAString& inAttribute,
                         nsAString& outValue);
-static void GetWindowType(nsIXULWindow* inWindow, nsString& outType);
+static void GetWindowType(nsIAppWindow* inWindow, nsString& outType);

 static Element* GetElementFromDocShell(nsIDocShell* aShell) {
  nsCOMPtr<nsIContentViewer> cv;
@ -41,7 +41,7 @@ static Element* GetElementFromDocShell(nsIDocShell* aShell) {
 }

 // generic "retrieve the value of a XUL attribute" function
-void GetAttribute(nsIXULWindow* inWindow, const nsAString& inAttribute,
+void GetAttribute(nsIAppWindow* inWindow, const nsAString& inAttribute,
                  nsAString& outValue) {
  nsCOMPtr<nsIDocShell> shell;
  if (inWindow && NS_SUCCEEDED(inWindow->GetDocShell(getter_AddRefs(shell)))) {
@ -54,7 +54,7 @@ void GetAttribute(nsIXULWindow* inWindow, const nsAString& inAttribute,

 // retrieve the window type, stored as the value of a particular
 // attribute in its XUL window tag
-void GetWindowType(nsIXULWindow* aWindow, nsString& outType) {
+void GetWindowType(nsIAppWindow* aWindow, nsString& outType) {
  GetAttribute(aWindow, NS_LITERAL_STRING("windowtype"), outType);
 }

@ -62,10 +62,10 @@ void GetWindowType(nsIXULWindow* aWindow, nsString& outType) {
 // nsWindowInfo
 //

-nsWindowInfo::nsWindowInfo(nsIXULWindow* inWindow, int32_t inTimeStamp)
+nsWindowInfo::nsWindowInfo(nsIAppWindow* inWindow, int32_t inTimeStamp)
    : mWindow(inWindow),
      mTimeStamp(inTimeStamp),
-      mZLevel(nsIXULWindow::normalZ) {
+      mZLevel(nsIAppWindow::normalZ) {
  ReferenceSelf(true, true);
 }

@ -187,16 +187,16 @@ NS_IMETHODIMP nsASDOMWindowEnumerator::GetNext(nsISupports** retval) {
 }

 //
-// nsASXULWindowEnumerator
+// nsASAppWindowEnumerator
 //

-nsASXULWindowEnumerator::nsASXULWindowEnumerator(const char16_t* aTypeString,
+nsASAppWindowEnumerator::nsASAppWindowEnumerator(const char16_t* aTypeString,
                                                 nsWindowMediator& aMediator)
    : nsAppShellWindowEnumerator(aTypeString, aMediator) {}

-nsASXULWindowEnumerator::~nsASXULWindowEnumerator() {}
+nsASAppWindowEnumerator::~nsASAppWindowEnumerator() {}

-NS_IMETHODIMP nsASXULWindowEnumerator::GetNext(nsISupports** retval) {
+NS_IMETHODIMP nsASAppWindowEnumerator::GetNext(nsISupports** retval) {
  if (!retval) return NS_ERROR_INVALID_ARG;

  *retval = nullptr;
@ -225,7 +225,7 @@ nsWindowInfo* nsASDOMWindowEarlyToLateEnumerator::FindNext() {
  nsWindowInfo *info, *listEnd;
  bool allWindows = mType.IsEmpty();

-  // see nsXULWindowEarlyToLateEnumerator::FindNext
+  // see AppWindowEarlyToLateEnumerator::FindNext
  if (!mCurrentPosition) return nullptr;

  info = mCurrentPosition->mYounger;
@ -240,19 +240,19 @@ nsWindowInfo* nsASDOMWindowEarlyToLateEnumerator::FindNext() {
 }

 //
-// nsASXULWindowEarlyToLateEnumerator
+// nsASAppWindowEarlyToLateEnumerator
 //

-nsASXULWindowEarlyToLateEnumerator::nsASXULWindowEarlyToLateEnumerator(
+nsASAppWindowEarlyToLateEnumerator::nsASAppWindowEarlyToLateEnumerator(
    const char16_t* aTypeString, nsWindowMediator& aMediator)
-    : nsASXULWindowEnumerator(aTypeString, aMediator) {
+    : nsASAppWindowEnumerator(aTypeString, aMediator) {
  mCurrentPosition = aMediator.mOldestWindow;
  AdjustInitialPosition();
 }

-nsASXULWindowEarlyToLateEnumerator::~nsASXULWindowEarlyToLateEnumerator() {}
+nsASAppWindowEarlyToLateEnumerator::~nsASAppWindowEarlyToLateEnumerator() {}

-nsWindowInfo* nsASXULWindowEarlyToLateEnumerator::FindNext() {
+nsWindowInfo* nsASAppWindowEarlyToLateEnumerator::FindNext() {
  nsWindowInfo *info, *listEnd;
  bool allWindows = mType.IsEmpty();

@ -277,23 +277,23 @@ nsWindowInfo* nsASXULWindowEarlyToLateEnumerator::FindNext() {
 }

 //
-// nsASXULWindowFrontToBackEnumerator
+// nsASAppWindowFrontToBackEnumerator
 //

-nsASXULWindowFrontToBackEnumerator::nsASXULWindowFrontToBackEnumerator(
+nsASAppWindowFrontToBackEnumerator::nsASAppWindowFrontToBackEnumerator(
    const char16_t* aTypeString, nsWindowMediator& aMediator)
-    : nsASXULWindowEnumerator(aTypeString, aMediator) {
+    : nsASAppWindowEnumerator(aTypeString, aMediator) {
  mCurrentPosition = aMediator.mTopmostWindow;
  AdjustInitialPosition();
 }

-nsASXULWindowFrontToBackEnumerator::~nsASXULWindowFrontToBackEnumerator() {}
+nsASAppWindowFrontToBackEnumerator::~nsASAppWindowFrontToBackEnumerator() {}

-nsWindowInfo* nsASXULWindowFrontToBackEnumerator::FindNext() {
+nsWindowInfo* nsASAppWindowFrontToBackEnumerator::FindNext() {
  nsWindowInfo *info, *listEnd;
  bool allWindows = mType.IsEmpty();

-  // see nsXULWindowEarlyToLateEnumerator::FindNext
+  // see AppWindowEarlyToLateEnumerator::FindNext
  if (!mCurrentPosition) return nullptr;

  info = mCurrentPosition->mLower;
@ -308,24 +308,24 @@ nsWindowInfo* nsASXULWindowFrontToBackEnumerator::FindNext() {
 }

 //
-// nsASXULWindowBackToFrontEnumerator
+// nsASAppWindowBackToFrontEnumerator
 //

-nsASXULWindowBackToFrontEnumerator::nsASXULWindowBackToFrontEnumerator(
+nsASAppWindowBackToFrontEnumerator::nsASAppWindowBackToFrontEnumerator(
    const char16_t* aTypeString, nsWindowMediator& aMediator)
-    : nsASXULWindowEnumerator(aTypeString, aMediator) {
+    : nsASAppWindowEnumerator(aTypeString, aMediator) {
  mCurrentPosition =
      aMediator.mTopmostWindow ? aMediator.mTopmostWindow->mHigher : nullptr;
  AdjustInitialPosition();
 }

-nsASXULWindowBackToFrontEnumerator::~nsASXULWindowBackToFrontEnumerator() {}
+nsASAppWindowBackToFrontEnumerator::~nsASAppWindowBackToFrontEnumerator() {}

-nsWindowInfo* nsASXULWindowBackToFrontEnumerator::FindNext() {
+nsWindowInfo* nsASAppWindowBackToFrontEnumerator::FindNext() {
  nsWindowInfo *info, *listEnd;
  bool allWindows = mType.IsEmpty();

-  // see nsXULWindowEarlyToLateEnumerator::FindNext
+  // see AppWindowEarlyToLateEnumerator::FindNext
  if (!mCurrentPosition) return nullptr;

  info = mCurrentPosition->mHigher;
--- a/xpfe/appshell/nsAppShellWindowEnumerator.h
+++ b/xpfe/appshell/nsAppShellWindowEnumerator.h
@ -10,7 +10,7 @@
 #include "nsString.h"

 #include "nsSimpleEnumerator.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"

 class nsWindowMediator;

@ -19,10 +19,10 @@ class nsWindowMediator;
 //

 struct nsWindowInfo {
-  nsWindowInfo(nsIXULWindow* inWindow, int32_t inTimeStamp);
+  nsWindowInfo(nsIAppWindow* inWindow, int32_t inTimeStamp);
  ~nsWindowInfo();

-  nsCOMPtr<nsIXULWindow> mWindow;
+  nsCOMPtr<nsIAppWindow> mWindow;
  int32_t mTimeStamp;
  uint32_t mZLevel;

@ -72,14 +72,14 @@ class nsASDOMWindowEnumerator : public nsAppShellWindowEnumerator {
  NS_IMETHOD GetNext(nsISupports** retval) override;
 };

-class nsASXULWindowEnumerator : public nsAppShellWindowEnumerator {
+class nsASAppWindowEnumerator : public nsAppShellWindowEnumerator {
 public:
-  nsASXULWindowEnumerator(const char16_t* aTypeString,
+  nsASAppWindowEnumerator(const char16_t* aTypeString,
                          nsWindowMediator& inMediator);
-  virtual ~nsASXULWindowEnumerator();
+  virtual ~nsASAppWindowEnumerator();
  NS_IMETHOD GetNext(nsISupports** retval) override;

-  const nsID& DefaultInterface() override { return NS_GET_IID(nsIXULWindow); }
+  const nsID& DefaultInterface() override { return NS_GET_IID(nsIAppWindow); }
 };

 //
@ -97,34 +97,34 @@ class nsASDOMWindowEarlyToLateEnumerator : public nsASDOMWindowEnumerator {
  virtual nsWindowInfo* FindNext() override;
 };

-class nsASXULWindowEarlyToLateEnumerator : public nsASXULWindowEnumerator {
+class nsASAppWindowEarlyToLateEnumerator : public nsASAppWindowEnumerator {
 public:
-  nsASXULWindowEarlyToLateEnumerator(const char16_t* aTypeString,
+  nsASAppWindowEarlyToLateEnumerator(const char16_t* aTypeString,
                                     nsWindowMediator& inMediator);

-  virtual ~nsASXULWindowEarlyToLateEnumerator();
+  virtual ~nsASAppWindowEarlyToLateEnumerator();

 protected:
  virtual nsWindowInfo* FindNext() override;
 };

-class nsASXULWindowFrontToBackEnumerator : public nsASXULWindowEnumerator {
+class nsASAppWindowFrontToBackEnumerator : public nsASAppWindowEnumerator {
 public:
-  nsASXULWindowFrontToBackEnumerator(const char16_t* aTypeString,
+  nsASAppWindowFrontToBackEnumerator(const char16_t* aTypeString,
                                     nsWindowMediator& inMediator);

-  virtual ~nsASXULWindowFrontToBackEnumerator();
+  virtual ~nsASAppWindowFrontToBackEnumerator();

 protected:
  virtual nsWindowInfo* FindNext() override;
 };

-class nsASXULWindowBackToFrontEnumerator : public nsASXULWindowEnumerator {
+class nsASAppWindowBackToFrontEnumerator : public nsASAppWindowEnumerator {
 public:
-  nsASXULWindowBackToFrontEnumerator(const char16_t* aTypeString,
+  nsASAppWindowBackToFrontEnumerator(const char16_t* aTypeString,
                                     nsWindowMediator& inMediator);

-  virtual ~nsASXULWindowBackToFrontEnumerator();
+  virtual ~nsASAppWindowBackToFrontEnumerator();

 protected:
  virtual nsWindowInfo* FindNext() override;
--- a/xpfe/appshell/nsChromeTreeOwner.cpp
+++ b/xpfe/appshell/nsChromeTreeOwner.cpp
@ -6,7 +6,7 @@

 // Local Includes
 #include "nsChromeTreeOwner.h"
-#include "nsXULWindow.h"
+#include "AppWindow.h"

 // Helper Classes
 #include "nsString.h"
@ -43,7 +43,7 @@ const nsLiteralString kSpace(u" ");
 //***    nsChromeTreeOwner: Object Management
 //*****************************************************************************

-nsChromeTreeOwner::nsChromeTreeOwner() : mXULWindow(nullptr) {}
+nsChromeTreeOwner::nsChromeTreeOwner() : mAppWindow(nullptr) {}

 nsChromeTreeOwner::~nsChromeTreeOwner() {}

@ -71,24 +71,24 @@ NS_IMETHODIMP nsChromeTreeOwner::GetInterface(const nsIID& aIID, void** aSink) {
  NS_ENSURE_ARG_POINTER(aSink);

  if (aIID.Equals(NS_GET_IID(nsIPrompt))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->GetInterface(aIID, aSink);
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->GetInterface(aIID, aSink);
  }
  if (aIID.Equals(NS_GET_IID(nsIAuthPrompt))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->GetInterface(aIID, aSink);
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->GetInterface(aIID, aSink);
  }
  if (aIID.Equals(NS_GET_IID(nsIWebBrowserChrome))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->GetInterface(aIID, aSink);
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->GetInterface(aIID, aSink);
  }
  if (aIID.Equals(NS_GET_IID(nsIEmbeddingSiteWindow))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->GetInterface(aIID, aSink);
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->GetInterface(aIID, aSink);
  }
-  if (aIID.Equals(NS_GET_IID(nsIXULWindow))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->QueryInterface(aIID, aSink);
+  if (aIID.Equals(NS_GET_IID(nsIAppWindow))) {
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->QueryInterface(aIID, aSink);
  }

  return QueryInterface(aIID, aSink);
@ -101,75 +101,75 @@ NS_IMETHODIMP nsChromeTreeOwner::GetInterface(const nsIID& aIID, void** aSink) {
 NS_IMETHODIMP
 nsChromeTreeOwner::ContentShellAdded(nsIDocShellTreeItem* aContentShell,
                                     bool aPrimary) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->ContentShellAdded(aContentShell, aPrimary);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->ContentShellAdded(aContentShell, aPrimary);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::ContentShellRemoved(nsIDocShellTreeItem* aContentShell) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->ContentShellRemoved(aContentShell);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->ContentShellRemoved(aContentShell);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetPrimaryContentShell(
    nsIDocShellTreeItem** aShell) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPrimaryContentShell(aShell);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPrimaryContentShell(aShell);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::RemoteTabAdded(nsIRemoteTab* aTab, bool aPrimary) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->RemoteTabAdded(aTab, aPrimary);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->RemoteTabAdded(aTab, aPrimary);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::RemoteTabRemoved(nsIRemoteTab* aTab) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->RemoteTabRemoved(aTab);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->RemoteTabRemoved(aTab);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::GetPrimaryRemoteTab(nsIRemoteTab** aTab) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPrimaryRemoteTab(aTab);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPrimaryRemoteTab(aTab);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::GetPrimaryContentSize(int32_t* aWidth, int32_t* aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPrimaryContentSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPrimaryContentSize(aWidth, aHeight);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::SetPrimaryContentSize(int32_t aWidth, int32_t aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPrimaryContentSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPrimaryContentSize(aWidth, aHeight);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::GetRootShellSize(int32_t* aWidth, int32_t* aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetRootShellSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetRootShellSize(aWidth, aHeight);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::SetRootShellSize(int32_t aWidth, int32_t aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetRootShellSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetRootShellSize(aWidth, aHeight);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SizeShellTo(nsIDocShellTreeItem* aShellItem,
                                             int32_t aCX, int32_t aCY) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SizeShellTo(aShellItem, aCX, aCY);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SizeShellTo(aShellItem, aCX, aCY);
 }

 NS_IMETHODIMP
 nsChromeTreeOwner::SetPersistence(bool aPersistPosition, bool aPersistSize,
                                  bool aPersistSizeMode) {
-  NS_ENSURE_STATE(mXULWindow);
-  nsCOMPtr<dom::Element> docShellElement = mXULWindow->GetWindowDOMElement();
+  NS_ENSURE_STATE(mAppWindow);
+  nsCOMPtr<dom::Element> docShellElement = mAppWindow->GetWindowDOMElement();
  if (!docShellElement) return NS_ERROR_FAILURE;

  nsAutoString persistString;
@ -204,8 +204,8 @@ nsChromeTreeOwner::SetPersistence(bool aPersistPosition, bool aPersistSize,
 NS_IMETHODIMP
 nsChromeTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,
                                  bool* aPersistSizeMode) {
-  NS_ENSURE_STATE(mXULWindow);
-  nsCOMPtr<dom::Element> docShellElement = mXULWindow->GetWindowDOMElement();
+  NS_ENSURE_STATE(mAppWindow);
+  nsCOMPtr<dom::Element> docShellElement = mAppWindow->GetWindowDOMElement();
  if (!docShellElement) return NS_ERROR_FAILURE;

  nsAutoString persistString;
@ -227,8 +227,8 @@ nsChromeTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,

 NS_IMETHODIMP
 nsChromeTreeOwner::GetTabCount(uint32_t* aResult) {
-  if (mXULWindow) {
-    return mXULWindow->GetTabCount(aResult);
+  if (mAppWindow) {
+    return mAppWindow->GetTabCount(aResult);
  }

  *aResult = 0;
@ -237,8 +237,8 @@ nsChromeTreeOwner::GetTabCount(uint32_t* aResult) {

 NS_IMETHODIMP
 nsChromeTreeOwner::GetHasPrimaryContent(bool* aResult) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetHasPrimaryContent(aResult);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetHasPrimaryContent(aResult);
 }

 //*****************************************************************************
@ -261,69 +261,69 @@ NS_IMETHODIMP nsChromeTreeOwner::Create() {
 }

 NS_IMETHODIMP nsChromeTreeOwner::Destroy() {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->Destroy();
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->Destroy();
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetUnscaledDevicePixelsPerCSSPixel(
    double* aScale) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetUnscaledDevicePixelsPerCSSPixel(aScale);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetUnscaledDevicePixelsPerCSSPixel(aScale);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetDevicePixelsPerDesktopPixel(
    double* aScale) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetDevicePixelsPerDesktopPixel(aScale);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetDevicePixelsPerDesktopPixel(aScale);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetPositionDesktopPix(int32_t x, int32_t y) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPositionDesktopPix(x, y);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPositionDesktopPix(x, y);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetPosition(int32_t x, int32_t y) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPosition(x, y);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPosition(x, y);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetPosition(int32_t* x, int32_t* y) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPosition(x, y);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPosition(x, y);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetSize(int32_t cx, int32_t cy,
                                         bool fRepaint) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetSize(cx, cy, fRepaint);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetSize(cx, cy, fRepaint);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetSize(int32_t* cx, int32_t* cy) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetSize(cx, cy);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetSize(cx, cy);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetPositionAndSize(int32_t x, int32_t y,
                                                    int32_t cx, int32_t cy,
                                                    uint32_t aFlags) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPositionAndSize(x, y, cx, cy, aFlags);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPositionAndSize(x, y, cx, cy, aFlags);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetPositionAndSize(int32_t* x, int32_t* y,
                                                    int32_t* cx, int32_t* cy) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPositionAndSize(x, y, cx, cy);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPositionAndSize(x, y, cx, cy);
 }

 NS_IMETHODIMP nsChromeTreeOwner::Repaint(bool aForce) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->Repaint(aForce);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->Repaint(aForce);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetParentWidget(nsIWidget** aParentWidget) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetParentWidget(aParentWidget);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetParentWidget(aParentWidget);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetParentWidget(nsIWidget* aParentWidget) {
@ -333,8 +333,8 @@ NS_IMETHODIMP nsChromeTreeOwner::SetParentWidget(nsIWidget* aParentWidget) {

 NS_IMETHODIMP nsChromeTreeOwner::GetParentNativeWindow(
    nativeWindow* aParentNativeWindow) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetParentNativeWindow(aParentNativeWindow);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetParentNativeWindow(aParentNativeWindow);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetParentNativeWindow(
@ -344,53 +344,53 @@ NS_IMETHODIMP nsChromeTreeOwner::SetParentNativeWindow(
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetNativeHandle(nsAString& aNativeHandle) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetNativeHandle(aNativeHandle);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetNativeHandle(aNativeHandle);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetVisibility(bool* aVisibility) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetVisibility(aVisibility);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetVisibility(aVisibility);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetVisibility(bool aVisibility) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetVisibility(aVisibility);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetVisibility(aVisibility);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetEnabled(bool* aEnabled) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetEnabled(aEnabled);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetEnabled(aEnabled);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetEnabled(bool aEnable) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetEnabled(aEnable);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetEnabled(aEnable);
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetMainWidget(nsIWidget** aMainWidget) {
  NS_ENSURE_ARG_POINTER(aMainWidget);
-  NS_ENSURE_STATE(mXULWindow);
+  NS_ENSURE_STATE(mAppWindow);

-  *aMainWidget = mXULWindow->mWindow;
+  *aMainWidget = mAppWindow->mWindow;
  NS_IF_ADDREF(*aMainWidget);

  return NS_OK;
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetFocus() {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetFocus();
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetFocus();
 }

 NS_IMETHODIMP nsChromeTreeOwner::GetTitle(nsAString& aTitle) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetTitle(aTitle);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetTitle(aTitle);
 }

 NS_IMETHODIMP nsChromeTreeOwner::SetTitle(const nsAString& aTitle) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetTitle(aTitle);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetTitle(aTitle);
 }

 //*****************************************************************************
@ -419,12 +419,12 @@ NS_IMETHODIMP
 nsChromeTreeOwner::OnLocationChange(nsIWebProgress* aWebProgress,
                                    nsIRequest* aRequest, nsIURI* aLocation,
                                    uint32_t aFlags) {
-  NS_ENSURE_STATE(mXULWindow);
+  NS_ENSURE_STATE(mAppWindow);

  // If loading a new root .xul document, then redo chrome.
  if (aWebProgress) {
    nsCOMPtr<nsIDocShell> docshell;
-    mXULWindow->GetDocShell(getter_AddRefs(docshell));
+    mAppWindow->GetDocShell(getter_AddRefs(docshell));

    nsCOMPtr<nsIWebProgress> webProgress(do_QueryInterface(docshell));
    if (webProgress != aWebProgress) {
@ -432,7 +432,7 @@ nsChromeTreeOwner::OnLocationChange(nsIWebProgress* aWebProgress,
    }
  }

-  mXULWindow->mChromeLoaded = false;
+  mAppWindow->mChromeLoaded = false;
  return NS_OK;
 }

@ -464,8 +464,8 @@ nsChromeTreeOwner::OnContentBlockingEvent(nsIWebProgress* aWebProgress,
 // nsChromeTreeOwner: Accessors
 //*****************************************************************************

-void nsChromeTreeOwner::XULWindow(nsXULWindow* aXULWindow) {
-  mXULWindow = aXULWindow;
+void nsChromeTreeOwner::AppWindow(mozilla::AppWindow* aAppWindow) {
+  mAppWindow = aAppWindow;
 }

-nsXULWindow* nsChromeTreeOwner::XULWindow() { return mXULWindow; }
+mozilla::AppWindow* nsChromeTreeOwner::AppWindow() { return mAppWindow; }
--- a/xpfe/appshell/nsChromeTreeOwner.h
+++ b/xpfe/appshell/nsChromeTreeOwner.h
@ -18,14 +18,16 @@
 #include "nsIWebProgressListener.h"
 #include "nsWeakReference.h"

-class nsXULWindow;
+namespace mozilla {
+class AppWindow;
+}

 class nsChromeTreeOwner : public nsIDocShellTreeOwner,
                          public nsIBaseWindow,
                          public nsIInterfaceRequestor,
                          public nsIWebProgressListener,
                          public nsSupportsWeakReference {
-  friend class nsXULWindow;
+  friend class mozilla::AppWindow;

 public:
  NS_DECL_ISUPPORTS
@ -39,11 +41,11 @@ class nsChromeTreeOwner : public nsIDocShellTreeOwner,
  nsChromeTreeOwner();
  virtual ~nsChromeTreeOwner();

-  void XULWindow(nsXULWindow* aXULWindow);
-  nsXULWindow* XULWindow();
+  void AppWindow(mozilla::AppWindow* aAppWindow);
+  mozilla::AppWindow* AppWindow();

 protected:
-  nsXULWindow* mXULWindow;
+  mozilla::AppWindow* mAppWindow;
 };

 #endif /* nsChromeTreeOwner_h__ */
--- a/xpfe/appshell/nsContentTreeOwner.cpp
+++ b/xpfe/appshell/nsContentTreeOwner.cpp
@ -7,7 +7,7 @@

 // Local Includes
 #include "nsContentTreeOwner.h"
-#include "nsXULWindow.h"
+#include "AppWindow.h"

 // Helper Classes
 #include "nsIServiceManager.h"
@ -78,7 +78,7 @@ class nsSiteWindow : public nsIEmbeddingSiteWindow {
 //*****************************************************************************

 nsContentTreeOwner::nsContentTreeOwner(bool fPrimary)
-    : mXULWindow(nullptr), mPrimary(fPrimary) {
+    : mAppWindow(nullptr), mPrimary(fPrimary) {
  // note if this fails, QI on nsIEmbeddingSiteWindow(2) will simply fail
  mSiteWindow = new nsSiteWindow(this);
 }
@ -122,26 +122,26 @@ NS_IMETHODIMP nsContentTreeOwner::GetInterface(const nsIID& aIID,
  *aSink = 0;

  if (aIID.Equals(NS_GET_IID(nsIPrompt))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->GetInterface(aIID, aSink);
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->GetInterface(aIID, aSink);
  }
  if (aIID.Equals(NS_GET_IID(nsIAuthPrompt))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->GetInterface(aIID, aSink);
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->GetInterface(aIID, aSink);
  }
  if (aIID.Equals(NS_GET_IID(nsIDocShellTreeItem))) {
-    NS_ENSURE_STATE(mXULWindow);
+    NS_ENSURE_STATE(mAppWindow);
    nsCOMPtr<nsIDocShell> shell;
-    mXULWindow->GetDocShell(getter_AddRefs(shell));
+    mAppWindow->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))) {
-    NS_ENSURE_STATE(mXULWindow);
+    NS_ENSURE_STATE(mAppWindow);
    nsCOMPtr<nsIDocShellTreeItem> shell;
-    mXULWindow->GetPrimaryContentShell(getter_AddRefs(shell));
+    mAppWindow->GetPrimaryContentShell(getter_AddRefs(shell));
    if (shell) {
      nsCOMPtr<nsIInterfaceRequestor> thing(do_QueryInterface(shell));
      if (thing) return thing->GetInterface(aIID, aSink);
@ -149,9 +149,9 @@ NS_IMETHODIMP nsContentTreeOwner::GetInterface(const nsIID& aIID,
    return NS_ERROR_FAILURE;
  }

-  if (aIID.Equals(NS_GET_IID(nsIXULWindow))) {
-    NS_ENSURE_STATE(mXULWindow);
-    return mXULWindow->QueryInterface(aIID, aSink);
+  if (aIID.Equals(NS_GET_IID(nsIAppWindow))) {
+    NS_ENSURE_STATE(mAppWindow);
+    return mAppWindow->QueryInterface(aIID, aSink);
  }

  return QueryInterface(aIID, aSink);
@ -164,75 +164,75 @@ NS_IMETHODIMP nsContentTreeOwner::GetInterface(const nsIID& aIID,
 NS_IMETHODIMP
 nsContentTreeOwner::ContentShellAdded(nsIDocShellTreeItem* aContentShell,
                                      bool aPrimary) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->ContentShellAdded(aContentShell, aPrimary);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->ContentShellAdded(aContentShell, aPrimary);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::ContentShellRemoved(nsIDocShellTreeItem* aContentShell) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->ContentShellRemoved(aContentShell);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->ContentShellRemoved(aContentShell);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::GetPrimaryContentShell(nsIDocShellTreeItem** aShell) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPrimaryContentShell(aShell);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPrimaryContentShell(aShell);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::RemoteTabAdded(nsIRemoteTab* aTab, bool aPrimary) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->RemoteTabAdded(aTab, aPrimary);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->RemoteTabAdded(aTab, aPrimary);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::RemoteTabRemoved(nsIRemoteTab* aTab) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->RemoteTabRemoved(aTab);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->RemoteTabRemoved(aTab);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::GetPrimaryRemoteTab(nsIRemoteTab** aTab) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPrimaryRemoteTab(aTab);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPrimaryRemoteTab(aTab);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::GetPrimaryContentSize(int32_t* aWidth, int32_t* aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPrimaryContentSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPrimaryContentSize(aWidth, aHeight);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::SetPrimaryContentSize(int32_t aWidth, int32_t aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPrimaryContentSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPrimaryContentSize(aWidth, aHeight);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::GetRootShellSize(int32_t* aWidth, int32_t* aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetRootShellSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetRootShellSize(aWidth, aHeight);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::SetRootShellSize(int32_t aWidth, int32_t aHeight) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetRootShellSize(aWidth, aHeight);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetRootShellSize(aWidth, aHeight);
 }

 NS_IMETHODIMP nsContentTreeOwner::SizeShellTo(nsIDocShellTreeItem* aShellItem,
                                              int32_t aCX, int32_t aCY) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SizeShellTo(aShellItem, aCX, aCY);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SizeShellTo(aShellItem, aCX, aCY);
 }

 NS_IMETHODIMP
 nsContentTreeOwner::SetPersistence(bool aPersistPosition, bool aPersistSize,
                                   bool aPersistSizeMode) {
-  NS_ENSURE_STATE(mXULWindow);
-  nsCOMPtr<dom::Element> docShellElement = mXULWindow->GetWindowDOMElement();
+  NS_ENSURE_STATE(mAppWindow);
+  nsCOMPtr<dom::Element> docShellElement = mAppWindow->GetWindowDOMElement();
  if (!docShellElement) return NS_ERROR_FAILURE;

  nsAutoString persistString;
@ -299,8 +299,8 @@ nsContentTreeOwner::SetPersistence(bool aPersistPosition, bool aPersistSize,
 NS_IMETHODIMP
 nsContentTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,
                                   bool* aPersistSizeMode) {
-  NS_ENSURE_STATE(mXULWindow);
-  nsCOMPtr<dom::Element> docShellElement = mXULWindow->GetWindowDOMElement();
+  NS_ENSURE_STATE(mAppWindow);
+  nsCOMPtr<dom::Element> docShellElement = mAppWindow->GetWindowDOMElement();
  if (!docShellElement) return NS_ERROR_FAILURE;

  nsAutoString persistString;
@ -326,8 +326,8 @@ nsContentTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,

 NS_IMETHODIMP
 nsContentTreeOwner::GetTabCount(uint32_t* aResult) {
-  if (mXULWindow) {
-    return mXULWindow->GetTabCount(aResult);
+  if (mAppWindow) {
+    return mAppWindow->GetTabCount(aResult);
  }

  *aResult = 0;
@ -336,8 +336,8 @@ nsContentTreeOwner::GetTabCount(uint32_t* aResult) {

 NS_IMETHODIMP
 nsContentTreeOwner::GetHasPrimaryContent(bool* aResult) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetHasPrimaryContent(aResult);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetHasPrimaryContent(aResult);
 }

 //*****************************************************************************
@ -347,10 +347,10 @@ nsContentTreeOwner::GetHasPrimaryContent(bool* aResult) {
 NS_IMETHODIMP nsContentTreeOwner::OnBeforeLinkTraversal(
    const nsAString& originalTarget, nsIURI* linkURI, nsINode* linkNode,
    bool isAppTab, nsAString& _retval) {
-  NS_ENSURE_STATE(mXULWindow);
+  NS_ENSURE_STATE(mAppWindow);

  nsCOMPtr<nsIXULBrowserWindow> xulBrowserWindow;
-  mXULWindow->GetXULBrowserWindow(getter_AddRefs(xulBrowserWindow));
+  mAppWindow->GetXULBrowserWindow(getter_AddRefs(xulBrowserWindow));

  if (xulBrowserWindow)
    return xulBrowserWindow->OnBeforeLinkTraversal(originalTarget, linkURI,
@ -364,10 +364,10 @@ NS_IMETHODIMP nsContentTreeOwner::ShouldLoadURI(
    nsIDocShell* aDocShell, nsIURI* aURI, nsIReferrerInfo* aReferrerInfo,
    bool aHasPostData, nsIPrincipal* aTriggeringPrincipal,
    nsIContentSecurityPolicy* aCsp, bool* _retval) {
-  NS_ENSURE_STATE(mXULWindow);
+  NS_ENSURE_STATE(mAppWindow);

  nsCOMPtr<nsIXULBrowserWindow> xulBrowserWindow;
-  mXULWindow->GetXULBrowserWindow(getter_AddRefs(xulBrowserWindow));
+  mAppWindow->GetXULBrowserWindow(getter_AddRefs(xulBrowserWindow));

  if (xulBrowserWindow)
    return xulBrowserWindow->ShouldLoadURI(aDocShell, aURI, aReferrerInfo,
@ -404,10 +404,10 @@ NS_IMETHODIMP nsContentTreeOwner::SetStatusWithContext(
  // We only allow the status to be set from the primary content shell
  if (!mPrimary && aStatusType != STATUS_LINK) return NS_OK;

-  NS_ENSURE_STATE(mXULWindow);
+  NS_ENSURE_STATE(mAppWindow);

  nsCOMPtr<nsIXULBrowserWindow> xulBrowserWindow;
-  mXULWindow->GetXULBrowserWindow(getter_AddRefs(xulBrowserWindow));
+  mAppWindow->GetXULBrowserWindow(getter_AddRefs(xulBrowserWindow));

  if (xulBrowserWindow) {
    switch (aStatusType) {
@ -436,23 +436,23 @@ NS_IMETHODIMP nsContentTreeOwner::SetStatus(uint32_t aStatusType,
 }

 NS_IMETHODIMP nsContentTreeOwner::SetChromeFlags(uint32_t aChromeFlags) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetChromeFlags(aChromeFlags);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetChromeFlags(aChromeFlags);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetChromeFlags(uint32_t* aChromeFlags) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetChromeFlags(aChromeFlags);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetChromeFlags(aChromeFlags);
 }

 NS_IMETHODIMP nsContentTreeOwner::ShowAsModal() {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->ShowModal();
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->ShowModal();
 }

 NS_IMETHODIMP nsContentTreeOwner::IsWindowModal(bool* _retval) {
-  NS_ENSURE_STATE(mXULWindow);
-  *_retval = mXULWindow->mContinueModalLoop;
+  NS_ENSURE_STATE(mAppWindow);
+  *_retval = mAppWindow->mContinueModalLoop;
  return NS_OK;
 }

@ -477,71 +477,71 @@ NS_IMETHODIMP nsContentTreeOwner::Create() {
 }

 NS_IMETHODIMP nsContentTreeOwner::Destroy() {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->Destroy();
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->Destroy();
 }

 NS_IMETHODIMP nsContentTreeOwner::GetUnscaledDevicePixelsPerCSSPixel(
    double* aScale) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetUnscaledDevicePixelsPerCSSPixel(aScale);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetUnscaledDevicePixelsPerCSSPixel(aScale);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetDevicePixelsPerDesktopPixel(
    double* aScale) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetDevicePixelsPerDesktopPixel(aScale);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetDevicePixelsPerDesktopPixel(aScale);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetPositionDesktopPix(int32_t aX,
                                                        int32_t aY) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPositionDesktopPix(aX, aY);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPositionDesktopPix(aX, aY);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetPosition(int32_t aX, int32_t aY) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPosition(aX, aY);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPosition(aX, aY);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetPosition(int32_t* aX, int32_t* aY) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPosition(aX, aY);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPosition(aX, aY);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetSize(int32_t aCX, int32_t aCY,
                                          bool aRepaint) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetSize(aCX, aCY, aRepaint);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetSize(aCX, aCY, aRepaint);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetSize(int32_t* aCX, int32_t* aCY) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetSize(aCX, aCY);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetSize(aCX, aCY);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetPositionAndSize(int32_t aX, int32_t aY,
                                                     int32_t aCX, int32_t aCY,
                                                     uint32_t aFlags) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetPositionAndSize(aX, aY, aCX, aCY, aFlags);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetPositionAndSize(aX, aY, aCX, aCY, aFlags);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetPositionAndSize(int32_t* aX, int32_t* aY,
                                                     int32_t* aCX,
                                                     int32_t* aCY) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetPositionAndSize(aX, aY, aCX, aCY);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetPositionAndSize(aX, aY, aCX, aCY);
 }

 NS_IMETHODIMP nsContentTreeOwner::Repaint(bool aForce) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->Repaint(aForce);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->Repaint(aForce);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetParentWidget(nsIWidget** aParentWidget) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetParentWidget(aParentWidget);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetParentWidget(aParentWidget);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetParentWidget(nsIWidget* aParentWidget) {
@ -551,8 +551,8 @@ NS_IMETHODIMP nsContentTreeOwner::SetParentWidget(nsIWidget* aParentWidget) {

 NS_IMETHODIMP nsContentTreeOwner::GetParentNativeWindow(
    nativeWindow* aParentNativeWindow) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetParentNativeWindow(aParentNativeWindow);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetParentNativeWindow(aParentNativeWindow);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetParentNativeWindow(
@ -562,49 +562,49 @@ NS_IMETHODIMP nsContentTreeOwner::SetParentNativeWindow(
 }

 NS_IMETHODIMP nsContentTreeOwner::GetNativeHandle(nsAString& aNativeHandle) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetNativeHandle(aNativeHandle);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetNativeHandle(aNativeHandle);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetVisibility(bool* aVisibility) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetVisibility(aVisibility);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetVisibility(aVisibility);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetVisibility(bool aVisibility) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetVisibility(aVisibility);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetVisibility(aVisibility);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetEnabled(bool* aEnabled) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->GetEnabled(aEnabled);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->GetEnabled(aEnabled);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetEnabled(bool aEnable) {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetEnabled(aEnable);
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetEnabled(aEnable);
 }

 NS_IMETHODIMP nsContentTreeOwner::GetMainWidget(nsIWidget** aMainWidget) {
  NS_ENSURE_ARG_POINTER(aMainWidget);
-  NS_ENSURE_STATE(mXULWindow);
+  NS_ENSURE_STATE(mAppWindow);

-  *aMainWidget = mXULWindow->mWindow;
+  *aMainWidget = mAppWindow->mWindow;
  NS_IF_ADDREF(*aMainWidget);

  return NS_OK;
 }

 NS_IMETHODIMP nsContentTreeOwner::SetFocus() {
-  NS_ENSURE_STATE(mXULWindow);
-  return mXULWindow->SetFocus();
+  NS_ENSURE_STATE(mAppWindow);
+  return mAppWindow->SetFocus();
 }

 NS_IMETHODIMP nsContentTreeOwner::GetTitle(nsAString& aTitle) {
-  NS_ENSURE_STATE(mXULWindow);
+  NS_ENSURE_STATE(mAppWindow);

-  return mXULWindow->GetTitle(aTitle);
+  return mAppWindow->GetTitle(aTitle);
 }

 NS_IMETHODIMP nsContentTreeOwner::SetTitle(const nsAString& aTitle) {
@ -629,7 +629,7 @@ nsContentTreeOwner::ProvideWindow(

  *aReturn = nullptr;

-  if (!mXULWindow) {
+  if (!mAppWindow) {
    // Nothing to do here
    return NS_OK;
  }
@ -690,11 +690,11 @@ nsContentTreeOwner::ProvideWindow(
  }

  nsCOMPtr<mozIDOMWindowProxy> domWin;
-  mXULWindow->GetWindowDOMWindow(getter_AddRefs(domWin));
+  mAppWindow->GetWindowDOMWindow(getter_AddRefs(domWin));
  nsCOMPtr<nsIDOMChromeWindow> chromeWin = do_QueryInterface(domWin);
  if (!chromeWin) {
    // Really odd... but whatever
-    NS_WARNING("nsXULWindow's DOMWindow is not a chrome window");
+    NS_WARNING("AppWindow's DOMWindow is not a chrome window");
    return NS_OK;
  }

@ -756,11 +756,11 @@ class nsContentTitleSettingEvent : public Runnable {
 };
 #endif

-void nsContentTreeOwner::XULWindow(nsXULWindow* aXULWindow) {
-  mXULWindow = aXULWindow;
+void nsContentTreeOwner::AppWindow(mozilla::AppWindow* aAppWindow) {
+  mAppWindow = aAppWindow;
 }

-nsXULWindow* nsContentTreeOwner::XULWindow() { return mXULWindow; }
+mozilla::AppWindow* nsContentTreeOwner::AppWindow() { return mAppWindow; }

 //*****************************************************************************
 //*** nsSiteWindow implementation
@ -804,7 +804,7 @@ nsSiteWindow::SetFocus(void) {
     and it's better for our purposes to not pick a document and
     focus it, but allow nsGlobalWindow to carry on unhindered.
  */
-  nsXULWindow *window = mAggregator->XULWindow();
+  AppWindow *window = mAggregator->AppWindow();
  if (window) {
    nsCOMPtr<nsIDocShell> docshell;
    window->GetDocShell(getter_AddRefs(docshell));
@ -825,15 +825,15 @@ nsSiteWindow::Blur(void) {
  NS_DEFINE_CID(kWindowMediatorCID, NS_WINDOWMEDIATOR_CID);

  nsCOMPtr<nsISimpleEnumerator> windowEnumerator;
-  nsCOMPtr<nsIXULWindow> xulWindow;
+  nsCOMPtr<nsIAppWindow> appWindow;
  bool more, foundUs;
-  nsXULWindow* ourWindow = mAggregator->XULWindow();
+  AppWindow* ourWindow = mAggregator->AppWindow();

  {
    nsCOMPtr<nsIWindowMediator> windowMediator(
        do_GetService(kWindowMediatorCID));
    if (windowMediator)
-      windowMediator->GetZOrderXULWindowEnumerator(
+      windowMediator->GetZOrderAppWindowEnumerator(
          0, true, getter_AddRefs(windowEnumerator));
  }

@ -844,30 +844,30 @@ nsSiteWindow::Blur(void) {
  windowEnumerator->HasMoreElements(&more);
  while (more) {
    nsCOMPtr<nsISupports> nextWindow;
-    nsCOMPtr<nsIXULWindow> nextXULWindow;
+    nsCOMPtr<nsIAppWindow> nextAppWindow;

    windowEnumerator->GetNext(getter_AddRefs(nextWindow));
-    nextXULWindow = do_QueryInterface(nextWindow);
+    nextAppWindow = do_QueryInterface(nextWindow);

    // got it!(?)
    if (foundUs) {
-      xulWindow = nextXULWindow;
+      appWindow = nextAppWindow;
      break;
    }

    // remember the very first one, in case we have to wrap
-    if (!xulWindow) xulWindow = nextXULWindow;
+    if (!appWindow) appWindow = nextAppWindow;

    // look for us
-    if (nextXULWindow == ourWindow) foundUs = true;
+    if (nextAppWindow == ourWindow) foundUs = true;

    windowEnumerator->HasMoreElements(&more);
  }

  // change focus to the window we just found
-  if (xulWindow) {
+  if (appWindow) {
    nsCOMPtr<nsIDocShell> docshell;
-    xulWindow->GetDocShell(getter_AddRefs(docshell));
+    appWindow->GetDocShell(getter_AddRefs(docshell));
    if (!docshell) {
      return NS_OK;
    }
--- a/xpfe/appshell/nsContentTreeOwner.h
+++ b/xpfe/appshell/nsContentTreeOwner.h
@ -19,7 +19,9 @@
 #include "nsIWebBrowserChrome3.h"
 #include "nsIWindowProvider.h"

-class nsXULWindow;
+namespace mozilla {
+class AppWindow;
+}
 class nsSiteWindow;

 class nsContentTreeOwner final : public nsIDocShellTreeOwner,
@ -27,7 +29,7 @@ class nsContentTreeOwner final : public nsIDocShellTreeOwner,
                                 public nsIInterfaceRequestor,
                                 public nsIWebBrowserChrome3,
                                 public nsIWindowProvider {
-  friend class nsXULWindow;
+  friend class mozilla::AppWindow;
  friend class nsSiteWindow;

 public:
@ -45,11 +47,11 @@ class nsContentTreeOwner final : public nsIDocShellTreeOwner,
  explicit nsContentTreeOwner(bool fPrimary);
  virtual ~nsContentTreeOwner();

-  void XULWindow(nsXULWindow* aXULWindow);
-  nsXULWindow* XULWindow();
+  void AppWindow(mozilla::AppWindow* aAppWindow);
+  mozilla::AppWindow* AppWindow();

 protected:
-  nsXULWindow* mXULWindow;
+  mozilla::AppWindow* mAppWindow;
  nsSiteWindow* mSiteWindow;
  bool mPrimary;
 };
--- a/xpfe/appshell/nsIAppShellService.idl
+++ b/xpfe/appshell/nsIAppShellService.idl
@ -5,7 +5,7 @@

 #include "nsISupports.idl"

-interface nsIXULWindow;
+interface nsIAppWindow;
 interface nsIWindowlessBrowser;
 interface nsIURI;
 interface mozIDOMWindowProxy;
@ -42,7 +42,7 @@ interface nsIAppShellService : nsISupports
   *                      Can be left null.
   */
  const long SIZE_TO_CONTENT = -1;
-  nsIXULWindow createTopLevelWindow(in nsIXULWindow aParent,
+  nsIAppWindow createTopLevelWindow(in nsIAppWindow aParent,
                                    in nsIURI aUrl,
                                    in uint32_t aChromeMask,
                                    in long aInitialWidth,
@ -79,7 +79,7 @@ interface nsIAppShellService : nsISupports
   * @param aResult the hidden window.  Do not unhide hidden window.
   *                Do not taunt hidden window.
   */
-  readonly attribute nsIXULWindow hiddenWindow;
+  readonly attribute nsIAppWindow hiddenWindow;

  /**
   * Return the (singleton) application hidden window, automatically created
@ -104,7 +104,7 @@ interface nsIAppShellService : nsISupports
   * @note When this method is successful, it fires the global notification
   *       "xul-window-registered"
   */
-  void registerTopLevelWindow(in nsIXULWindow aWindow);
+  void registerTopLevelWindow(in nsIAppWindow aWindow);

  /**
   * Remove a window from the application's window registry. Note that
@ -112,7 +112,7 @@ interface nsIAppShellService : nsISupports
   * the last window is unregistered. For that, see Quit().
   * @param aWindow you see the pattern
   */
-  void unregisterTopLevelWindow(in nsIXULWindow aWindow);
+  void unregisterTopLevelWindow(in nsIAppWindow aWindow);

  /**
   * Whether the hidden window has been lazily created.
--- a/xpfe/appshell/nsIAppWindow.idl
+++ b/xpfe/appshell/nsIAppWindow.idl
@ -7,7 +7,7 @@
 #include "nsISupports.idl"

 /**
- * The nsIXULWindow
+ * The nsIAppWindow
 *
 * When the window is destroyed, it will fire a "xul-window-destroyed"
 * notification through the global observer service.
@ -27,7 +27,7 @@ interface mozIDOMWindowProxy;
 native LiveResizeListenerArray(nsTArray<RefPtr<mozilla::LiveResizeListener>>);

 [builtinclass, scriptable, uuid(d6d7a014-e28d-4c9d-8727-1cf6d870619b)]
-interface nsIXULWindow : nsISupports
+interface nsIAppWindow : nsISupports
 {
  /**
   * The docshell owning the XUL for this window.
@ -64,7 +64,7 @@ interface nsIXULWindow : nsISupports
   * Tell this window that it has picked up a child XUL window
   * @param aChild the child window being added
   */
-  void addChildWindow(in nsIXULWindow aChild);
+  void addChildWindow(in nsIAppWindow aChild);

  /**
   * Returns the difference between the inner window size (client size) and the
@ -77,7 +77,7 @@ interface nsIXULWindow : nsISupports
   * Tell this window that it has lost a child XUL window
   * @param aChild the child window being removed
   */
-  void removeChildWindow(in nsIXULWindow aChild);
+  void removeChildWindow(in nsIAppWindow aChild);

  /**
   * Move the window to a centered position.
@ -93,7 +93,7 @@ interface nsIXULWindow : nsISupports
   * @param aAlert    PR_TRUE to move the window to an alert position,
   *                  generally centered horizontally and 1/3 down from the top.
   */
-  void center(in nsIXULWindow aRelative, in boolean aScreen, in boolean aAlert);
+  void center(in nsIAppWindow aRelative, in boolean aScreen, in boolean aAlert);

  /**
   * Shows the window as a modal window. That is, ensures that it is visible
@ -133,7 +133,7 @@ interface nsIXULWindow : nsISupports
   *        0 means there is no next remote tab actor to use.
   * @return the newly minted window
   */
-  nsIXULWindow createNewWindow(in int32_t aChromeFlags,
+  nsIAppWindow createNewWindow(in int32_t aChromeFlags,
                               in nsIRemoteTab aOpeningTab,
                               in mozIDOMWindowProxy aOpener,
                               in unsigned long long aNextRemoteTabId);
--- a/xpfe/appshell/nsIWindowMediator.idl
+++ b/xpfe/appshell/nsIWindowMediator.idl
@ -17,7 +17,7 @@

 interface mozIDOMWindow;
 interface mozIDOMWindowProxy;
-interface nsIXULWindow;
+interface nsIAppWindow;
 interface nsIWidget;
 interface nsIWindowMediatorListener;

@ -37,9 +37,9 @@ interface nsIWindowMediator: nsISupports
  nsISimpleEnumerator getEnumerator(in wstring aWindowType);

  /** Identical to getEnumerator except:
-    * @return an enumerator of nsIXULWindows
+    * @return an enumerator of nsIAppWindows
  */
-  nsISimpleEnumerator getXULWindowEnumerator(in wstring aWindowType);
+  nsISimpleEnumerator getAppWindowEnumerator(in wstring aWindowType);

  /** Return an enumerator which iterates over all windows of type aWindowType
    * in their z (front-to-back) order. Note this interface makes
@ -51,9 +51,9 @@ interface nsIWindowMediator: nsISupports
    *                     If null, all windows will be enumerated.
    * @param  aFrontToBack if true, the enumerator enumerates windows in order
    *                      from front to back. back to front if false.
-    * @return an enumerator of nsIXULWindows
+    * @return an enumerator of nsIAppWindows
    */
-  nsISimpleEnumerator getZOrderXULWindowEnumerator(in wstring aWindowType,
+  nsISimpleEnumerator getZOrderAppWindowEnumerator(in wstring aWindowType,
                        in boolean aFrontToBack);

  /** This is a shortcut for simply fetching the first window in
@ -95,20 +95,20 @@ interface nsIWindowMediator: nsISupports
    * addListener) will be notified through their onOpenWindow method.
    * @param aWindow the window to add
    */
-  [noscript] void registerWindow(in nsIXULWindow aWindow);
+  [noscript] void registerWindow(in nsIAppWindow aWindow);

  /** Remove the window from the list of known windows. Listeners (see
    * addListener) will be be notified through their onCloseWindow method.
    * @param aWindow the window to remove
    */
-  [noscript] void unregisterWindow(in nsIXULWindow aWindow);
+  [noscript] void unregisterWindow(in nsIAppWindow aWindow);

  /** Call this method when a window gains focus. It's a primitive means of
    * determining the most recent window. It's no longer necessary and it
    * really should be removed.
    * @param aWindow the window which has gained focus
    */
-  [noscript] void updateWindowTimeStamp(in nsIXULWindow aWindow);
+  [noscript] void updateWindowTimeStamp(in nsIAppWindow aWindow);

  /* z-ordering: */

@ -120,8 +120,8 @@ interface nsIWindowMediator: nsISupports
    * it should be constrained. Note this method is advisory only:
    * it changes nothing either in WindowMediator's internal state
    * or with the window.
-    * Note it compares the nsIXULWindow to nsIWidgets. A pure interface
-    * would use all nsIXULWindows. But we expect this to be called from
+    * Note it compares the nsIAppWindow to nsIWidgets. A pure interface
+    * would use all nsIAppWindows. But we expect this to be called from
    * callbacks originating in native window code. They are expected to
    * hand us comparison values which are pulled from general storage
    * in the native widget, and may not correspond to an nsIWidget at all.
@ -146,7 +146,7 @@ interface nsIWindowMediator: nsISupports
    *         the position given.
    */

-  [noscript] boolean calculateZPosition(in nsIXULWindow   inWindow,
+  [noscript] boolean calculateZPosition(in nsIAppWindow   inWindow,
                                        in unsigned long  inPosition,
                                        in nsIWidget      inBelow,
                                        out unsigned long outPosition,
@ -161,24 +161,24 @@ interface nsIWindowMediator: nsISupports
    *                                for other values of inPosition.)
    * @param inBelow the window inWindow is behind, if zLevelBelow
    */
-  [noscript] void setZPosition(in nsIXULWindow inWindow,
+  [noscript] void setZPosition(in nsIAppWindow inWindow,
                               in unsigned long inPosition,
-                               in nsIXULWindow inBelow);
+                               in nsIAppWindow inBelow);

-  /** Return the window's Z level (as defined in nsIXULWindow).
+  /** Return the window's Z level (as defined in nsIAppWindow).
    * @param aWindow the window in question
    * @return aWindow's z level
    */
-  [noscript] uint32_t getZLevel(in nsIXULWindow aWindow);
+  [noscript] uint32_t getZLevel(in nsIAppWindow aWindow);

-  /** Set the window's Z level (as defined in nsIXULWindow). The implementation
+  /** Set the window's Z level (as defined in nsIAppWindow). The implementation
    * will reposition the window as necessary to match its new Z level.
    * The implementation will assume a window's Z level to be
-    * nsIXULWindow::normalZ until it has been informed of a different level.
+    * nsIAppWindow::normalZ until it has been informed of a different level.
    * @param aWindow the window in question
    * @param aZLevel the window's new Z level
    */
-  [noscript] void setZLevel(in nsIXULWindow aWindow, in uint32_t aZLevel);
+  [noscript] void setZLevel(in nsIAppWindow aWindow, in uint32_t aZLevel);

  /** Register a listener for window status changes.
    * keeps strong ref? (to be decided)
--- a/xpfe/appshell/nsIWindowMediatorListener.idl
+++ b/xpfe/appshell/nsIWindowMediatorListener.idl
@ -5,12 +5,12 @@

 #include "nsISupports.idl"

-interface nsIXULWindow;
+interface nsIAppWindow;

 [scriptable, uuid(2F276982-0D60-4377-A595-D350BA516395)]
 interface nsIWindowMediatorListener : nsISupports
 {
-    void onOpenWindow(in nsIXULWindow window);
-    void onCloseWindow(in nsIXULWindow window);
+    void onOpenWindow(in nsIAppWindow window);
+    void onCloseWindow(in nsIAppWindow window);
 };

--- a/xpfe/appshell/nsWindowMediator.cpp
+++ b/xpfe/appshell/nsWindowMediator.cpp
@ -21,12 +21,12 @@
 #include "nsIDocShell.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
-#include "nsIXULWindow.h"
+#include "nsIAppWindow.h"

 using namespace mozilla;

 nsresult nsWindowMediator::GetDOMWindow(
-    nsIXULWindow* inWindow, nsCOMPtr<nsPIDOMWindowOuter>& outDOMWindow) {
+    nsIAppWindow* inWindow, nsCOMPtr<nsPIDOMWindowOuter>& outDOMWindow) {
  nsCOMPtr<nsIDocShell> docShell;

  outDOMWindow = nullptr;
@ -61,7 +61,7 @@ nsresult nsWindowMediator::Init() {
  return NS_OK;
 }

-NS_IMETHODIMP nsWindowMediator::RegisterWindow(nsIXULWindow* inWindow) {
+NS_IMETHODIMP nsWindowMediator::RegisterWindow(nsIAppWindow* inWindow) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  NS_ENSURE_STATE(mReady);

@ -89,7 +89,7 @@ NS_IMETHODIMP nsWindowMediator::RegisterWindow(nsIXULWindow* inWindow) {
 }

 NS_IMETHODIMP
-nsWindowMediator::UnregisterWindow(nsIXULWindow* inWindow) {
+nsWindowMediator::UnregisterWindow(nsIAppWindow* inWindow) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  NS_ENSURE_STATE(mReady);
  nsWindowInfo* info = GetInfoFor(inWindow);
@ -105,7 +105,7 @@ nsresult nsWindowMediator::UnregisterWindow(nsWindowInfo* inInfo) {
    index++;
  }

-  nsIXULWindow* window = inInfo->mWindow.get();
+  nsIAppWindow* window = inInfo->mWindow.get();
  ListenerArray::ForwardIterator iter(mListeners);
  while (iter.HasMore()) {
    iter.GetNext()->OnCloseWindow(window);
@ -122,7 +122,7 @@ nsresult nsWindowMediator::UnregisterWindow(nsWindowInfo* inInfo) {
  return NS_OK;
 }

-nsWindowInfo* nsWindowMediator::GetInfoFor(nsIXULWindow* aWindow) {
+nsWindowInfo* nsWindowMediator::GetInfoFor(nsIAppWindow* aWindow) {
  nsWindowInfo *info, *listEnd;

  if (!aWindow) return nullptr;
@ -170,20 +170,20 @@ nsWindowMediator::GetEnumerator(const char16_t* inType,
 }

 NS_IMETHODIMP
-nsWindowMediator::GetXULWindowEnumerator(const char16_t* inType,
+nsWindowMediator::GetAppWindowEnumerator(const char16_t* inType,
                                         nsISimpleEnumerator** outEnumerator) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  NS_ENSURE_ARG_POINTER(outEnumerator);
  NS_ENSURE_STATE(mReady);

  RefPtr<nsAppShellWindowEnumerator> enumerator =
-      new nsASXULWindowEarlyToLateEnumerator(inType, *this);
+      new nsASAppWindowEarlyToLateEnumerator(inType, *this);
  enumerator.forget(outEnumerator);
  return NS_OK;
 }

 NS_IMETHODIMP
-nsWindowMediator::GetZOrderXULWindowEnumerator(const char16_t* aWindowType,
+nsWindowMediator::GetZOrderAppWindowEnumerator(const char16_t* aWindowType,
                                               bool aFrontToBack,
                                               nsISimpleEnumerator** _retval) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
@ -192,9 +192,9 @@ nsWindowMediator::GetZOrderXULWindowEnumerator(const char16_t* aWindowType,

  RefPtr<nsAppShellWindowEnumerator> enumerator;
  if (aFrontToBack)
-    enumerator = new nsASXULWindowFrontToBackEnumerator(aWindowType, *this);
+    enumerator = new nsASAppWindowFrontToBackEnumerator(aWindowType, *this);
  else
-    enumerator = new nsASXULWindowBackToFrontEnumerator(aWindowType, *this);
+    enumerator = new nsASAppWindowBackToFrontEnumerator(aWindowType, *this);

  enumerator.forget(_retval);
  return NS_OK;
@ -344,7 +344,7 @@ nsWindowMediator::GetCurrentInnerWindowWithId(uint64_t aWindowID,
 }

 NS_IMETHODIMP
-nsWindowMediator::UpdateWindowTimeStamp(nsIXULWindow* inWindow) {
+nsWindowMediator::UpdateWindowTimeStamp(nsIAppWindow* inWindow) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  NS_ENSURE_STATE(mReady);
  nsWindowInfo* info = GetInfoFor(inWindow);
@ -363,7 +363,7 @@ nsWindowMediator::UpdateWindowTimeStamp(nsIXULWindow* inWindow) {
   calculate a change as seldom as possible.
 */
 NS_IMETHODIMP
-nsWindowMediator::CalculateZPosition(nsIXULWindow* inWindow,
+nsWindowMediator::CalculateZPosition(nsIAppWindow* inWindow,
                                     uint32_t inPosition, nsIWidget* inBelow,
                                     uint32_t* outPosition,
                                     nsIWidget** outBelow, bool* outAltered) {
@ -381,7 +381,7 @@ nsWindowMediator::CalculateZPosition(nsIXULWindow* inWindow,
    return NS_ERROR_INVALID_ARG;

  nsWindowInfo* info = mTopmostWindow;
-  nsIXULWindow* belowWindow = nullptr;
+  nsIAppWindow* belowWindow = nullptr;
  bool found = false;
  nsresult result = NS_OK;

@ -486,8 +486,8 @@ nsWindowMediator::CalculateZPosition(nsIXULWindow* inWindow,
 }

 NS_IMETHODIMP
-nsWindowMediator::SetZPosition(nsIXULWindow* inWindow, uint32_t inPosition,
-                               nsIXULWindow* inBelow) {
+nsWindowMediator::SetZPosition(nsIAppWindow* inWindow, uint32_t inPosition,
+                               nsIAppWindow* inBelow) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  nsWindowInfo *inInfo, *belowInfo;

@ -539,9 +539,9 @@ nsWindowMediator::SetZPosition(nsIXULWindow* inWindow, uint32_t inPosition,
 }

 NS_IMETHODIMP
-nsWindowMediator::GetZLevel(nsIXULWindow* aWindow, uint32_t* _retval) {
+nsWindowMediator::GetZLevel(nsIAppWindow* aWindow, uint32_t* _retval) {
  NS_ENSURE_ARG_POINTER(_retval);
-  *_retval = nsIXULWindow::normalZ;
+  *_retval = nsIAppWindow::normalZ;
  // This can fail during window destruction.
  nsWindowInfo* info = GetInfoFor(aWindow);
  if (info) {
@ -551,7 +551,7 @@ nsWindowMediator::GetZLevel(nsIXULWindow* aWindow, uint32_t* _retval) {
 }

 NS_IMETHODIMP
-nsWindowMediator::SetZLevel(nsIXULWindow* aWindow, uint32_t aZLevel) {
+nsWindowMediator::SetZLevel(nsIAppWindow* aWindow, uint32_t aZLevel) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  NS_ENSURE_STATE(mReady);

--- a/xpfe/appshell/nsWindowMediator.h
+++ b/xpfe/appshell/nsWindowMediator.h
@ -15,10 +15,10 @@
 #include "nsTObserverArray.h"

 class nsAppShellWindowEnumerator;
-class nsASXULWindowEarlyToLateEnumerator;
+class nsASAppWindowEarlyToLateEnumerator;
 class nsASDOMWindowEarlyToLateEnumerator;
-class nsASXULWindowFrontToBackEnumerator;
-class nsASXULWindowBackToFrontEnumerator;
+class nsASAppWindowFrontToBackEnumerator;
+class nsASAppWindowBackToFrontEnumerator;
 class nsIWindowMediatorListener;
 struct nsWindowInfo;

@ -26,10 +26,10 @@ class nsWindowMediator : public nsIWindowMediator,
                         public nsIObserver,
                         public nsSupportsWeakReference {
  friend class nsAppShellWindowEnumerator;
-  friend class nsASXULWindowEarlyToLateEnumerator;
+  friend class nsASAppWindowEarlyToLateEnumerator;
  friend class nsASDOMWindowEarlyToLateEnumerator;
-  friend class nsASXULWindowFrontToBackEnumerator;
-  friend class nsASXULWindowBackToFrontEnumerator;
+  friend class nsASAppWindowFrontToBackEnumerator;
+  friend class nsASAppWindowBackToFrontEnumerator;

 protected:
  virtual ~nsWindowMediator();
@ -43,7 +43,7 @@ class nsWindowMediator : public nsIWindowMediator,
  NS_DECL_NSIWINDOWMEDIATOR
  NS_DECL_NSIOBSERVER

-  static nsresult GetDOMWindow(nsIXULWindow* inWindow,
+  static nsresult GetDOMWindow(nsIAppWindow* inWindow,
                               nsCOMPtr<nsPIDOMWindowOuter>& outDOMWindow);

 private:
@ -53,7 +53,7 @@ class nsWindowMediator : public nsIWindowMediator,
                                     bool aSkipPrivateBrowsingOrClosed = false);

  nsresult UnregisterWindow(nsWindowInfo* inInfo);
-  nsWindowInfo* GetInfoFor(nsIXULWindow* aWindow);
+  nsWindowInfo* GetInfoFor(nsIAppWindow* aWindow);
  nsWindowInfo* GetInfoFor(nsIWidget* aWindow);
  void SortZOrderFrontToBack();
  void SortZOrderBackToFront();