From dba07065a9a9543f772dd98ff3d3358e72ce3c32 Mon Sep 17 00:00:00 2001
From: Riccardo Mottola <rm@gnu.org>
Date: Tue, 18 Dec 2018 22:04:23 +0100
Subject: [PATCH] first batch to transition nsIDOMWindow to nsPIDOMWindow at
 about TenFourFox level

---
 docshell/base/nsDSURIContentListener.cpp     |   5 +-
 docshell/base/nsDocShell.cpp                 |  27 ++-
 dom/base/ThirdPartyUtil.cpp                  |  19 +-
 dom/base/nsContentUtils.cpp                  |   9 +-
 dom/base/nsContentUtils.h                    |   2 +-
 dom/base/nsDocument.cpp                      |  14 +-
 dom/base/nsGlobalWindow.cpp                  | 180 +++++++++----------
 dom/base/nsGlobalWindow.h                    |  51 +++---
 dom/base/nsObjectLoadingContent.cpp          |  13 +-
 dom/base/nsPIDOMWindow.h                     |  17 ++
 dom/base/nsWindowMemoryReporter.cpp          |   6 +-
 dom/base/nsXMLHttpRequest.cpp                |   3 +-
 dom/browser-element/BrowserElementParent.cpp |   6 +-
 dom/events/EventStateManager.cpp             |  16 +-
 dom/html/nsGenericHTMLElement.cpp            |   6 +-
 dom/interfaces/base/nsIDOMWindow.idl         |  57 ------
 dom/plugins/base/nsPluginInstanceOwner.cpp   |   7 +-
 uriloader/base/nsDocLoader.cpp               |   5 +-
 18 files changed, 181 insertions(+), 262 deletions(-)

diff --git a/docshell/base/nsDSURIContentListener.cpp b/docshell/base/nsDSURIContentListener.cpp
index e72bdf49ccd..d0f65b63029 100755
--- a/docshell/base/nsDSURIContentListener.cpp
+++ b/docshell/base/nsDSURIContentListener.cpp
@@ -307,7 +307,7 @@ nsDSURIContentListener::CheckOneFrameOptionsPolicy(nsIHttpChannel* aHttpChannel,
   // window, if we're not the top.  X-F-O: SAMEORIGIN requires that the
   // document must be same-origin with top window.  X-F-O: DENY requires that
   // the document must never be framed.
-  nsCOMPtr<nsIDOMWindow> thisWindow = mDocShell->GetWindow();
+  nsCOMPtr<nsPIDOMWindow> thisWindow = mDocShell->GetWindow();
   // If we don't have DOMWindow there is no risk of clickjacking
   if (!thisWindow) {
     return true;
@@ -315,8 +315,7 @@ nsDSURIContentListener::CheckOneFrameOptionsPolicy(nsIHttpChannel* aHttpChannel,
 
   // GetScriptableTop, not GetTop, because we want this to respect
   // <iframe mozbrowser> boundaries.
-  nsCOMPtr<nsIDOMWindow> topWindow;
-  thisWindow->GetScriptableTop(getter_AddRefs(topWindow));
+  nsCOMPtr<nsPIDOMWindow> topWindow = thisWindow->GetScriptableTop();
 
   // if the document is in the top window, it's not in a frame.
   if (thisWindow == topWindow) {
diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index 29d803a068d..ecf0364a1a9 100755
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -3189,7 +3189,7 @@ nsDocShell::GetSessionStorageForPrincipal(nsIPrincipal* aPrincipal,
     return NS_ERROR_UNEXPECTED;
   }
 
-  nsCOMPtr<nsIDOMWindow> domWin = do_GetInterface(GetAsSupports(this));
+  nsCOMPtr<nsPIDOMWindow> domWin = do_GetInterface(GetAsSupports(this));
 
   if (aCreate) {
     return manager->CreateStorage(domWin, aPrincipal, aDocumentURI,
@@ -3697,7 +3697,7 @@ nsDocShell::CanAccessItem(nsIDocShellTreeItem* aTargetItem,
     return false;
   }
 
-  nsCOMPtr<nsIDOMWindow> targetWindow = aTargetItem->GetWindow();
+  nsCOMPtr<nsPIDOMWindow> targetWindow = aTargetItem->GetWindow();
   if (!targetWindow) {
     NS_ERROR("This should not happen, really");
     return false;
@@ -3718,7 +3718,7 @@ nsDocShell::CanAccessItem(nsIDocShellTreeItem* aTargetItem,
 static bool
 ItemIsActive(nsIDocShellTreeItem* aItem)
 {
-  nsCOMPtr<nsIDOMWindow> window = aItem->GetWindow();
+  nsCOMPtr<nsPIDOMWindow> window = aItem->GetWindow();
 
   if (window) {
     bool isClosed;
@@ -3978,7 +3978,7 @@ PrintDocTree(nsIDocShellTreeItem* aParentNode, int aLevel)
   parentAsDocShell->GetPresContext(getter_AddRefs(presContext));
   nsIDocument* doc = presShell->GetDocument();
 
-  nsCOMPtr<nsIDOMWindow> domwin(doc->GetWindow());
+  nsCOMPtr<nsPIDOMWindow> domwin(doc->GetWindow());
 
   nsCOMPtr<nsIWidget> widget;
   nsViewManager* vm = presShell->GetViewManager();
@@ -9940,7 +9940,7 @@ nsDocShell::InternalLoad(nsIURI* aURI,
           // So, the best we can do, is to tear down the new window
           // that was just created!
           //
-          nsCOMPtr<nsIDOMWindow> domWin = targetDocShell->GetWindow();
+          nsCOMPtr<nsPIDOMWindow> domWin = targetDocShell->GetWindow();
           if (domWin) {
             domWin->Close();
           }
@@ -13205,10 +13205,11 @@ nsDocShell::GetAssociatedWindow(nsIDOMWindow** aWindow)
 NS_IMETHODIMP
 nsDocShell::GetTopWindow(nsIDOMWindow** aWindow)
 {
-  nsCOMPtr<nsIDOMWindow> win = GetWindow();
+  nsCOMPtr<nsPIDOMWindow> win = GetWindow();
   if (win) {
-    win->GetTop(aWindow);
+    win = win->GetTop();
   }
+  win.forget(aWindow);
   return NS_OK;
 }
 
@@ -13216,23 +13217,19 @@ NS_IMETHODIMP
 nsDocShell::GetTopFrameElement(nsIDOMElement** aElement)
 {
   *aElement = nullptr;
-  nsCOMPtr<nsIDOMWindow> win = GetWindow();
+  nsCOMPtr<nsPIDOMWindow> win = GetWindow();
   if (!win) {
     return NS_OK;
   }
 
-  nsCOMPtr<nsIDOMWindow> top;
-  win->GetScriptableTop(getter_AddRefs(top));
+  nsCOMPtr<nsPIDOMWindow> top = win->GetScriptableTop();
   NS_ENSURE_TRUE(top, NS_ERROR_FAILURE);
 
-  nsCOMPtr<nsPIDOMWindow> piTop = do_QueryInterface(top);
-  NS_ENSURE_TRUE(piTop, NS_ERROR_FAILURE);
-
   // GetFrameElementInternal, /not/ GetScriptableFrameElement -- if |top| is
   // inside <iframe mozbrowser>, we want to return the iframe, not null.
   // And we want to cross the content/chrome boundary.
   nsCOMPtr<nsIDOMElement> elt =
-    do_QueryInterface(piTop->GetFrameElementInternal());
+    do_QueryInterface(top->GetFrameElementInternal());
   elt.forget(aElement);
   return NS_OK;
 }
@@ -13347,7 +13344,7 @@ nsDocShell::EnsureCommandHandler()
       return NS_ERROR_OUT_OF_MEMORY;
     }
 
-    nsCOMPtr<nsIDOMWindow> domWindow = GetWindow();
+    nsCOMPtr<nsPIDOMWindow> domWindow = GetWindow();
     nsresult rv = commandUpdater->Init(domWindow);
     if (NS_SUCCEEDED(rv)) {
       mCommandManager = do_QueryInterface(commandUpdater);
diff --git a/dom/base/ThirdPartyUtil.cpp b/dom/base/ThirdPartyUtil.cpp
index 83848dafb26..4a8014f7bdc 100755
--- a/dom/base/ThirdPartyUtil.cpp
+++ b/dom/base/ThirdPartyUtil.cpp
@@ -138,13 +138,12 @@ ThirdPartyUtil::IsThirdPartyWindow(nsIDOMWindow* aWindow,
     }
   }
 
-  nsCOMPtr<nsIDOMWindow> current = aWindow, parent;
+  nsCOMPtr<nsPIDOMWindow> current = do_QueryInterface(aWindow), parent;
   nsCOMPtr<nsIURI> parentURI;
   do {
     // We use GetScriptableParent rather than GetParent because we consider
     // <iframe mozbrowser/mozapp> to be a top-level frame.
-    rv = current->GetScriptableParent(getter_AddRefs(parent));
-    NS_ENSURE_SUCCESS(rv, rv);
+    parent = current->GetScriptableParent();
 
     if (SameCOMIdentity(parent, current)) {
       // We're at the topmost content window. We already know the answer.
@@ -267,13 +266,14 @@ ThirdPartyUtil::IsThirdPartyChannel(nsIChannel* aChannel,
   // to the channel. This is limited to loads of certain types of resources. If
   // those loads require cookies, the forceAllowThirdPartyCookie property should
   // be set on the channel.
-  nsCOMPtr<nsIDOMWindow> ourWin, parentWin;
+  nsCOMPtr<nsIDOMWindow> ourWin;
   ctx->GetAssociatedWindow(getter_AddRefs(ourWin));
   if (!ourWin) return NS_ERROR_INVALID_ARG;
 
   // We use GetScriptableParent rather than GetParent because we consider
   // <iframe mozbrowser/mozapp> to be a top-level frame.
-  ourWin->GetScriptableParent(getter_AddRefs(parentWin));
+  nsCOMPtr<nsPIDOMWindow> ourPWin = do_QueryInterface(ourWin);
+  nsCOMPtr<nsPIDOMWindow> parentWin = ourPWin->GetScriptableParent();
   NS_ENSURE_TRUE(parentWin, NS_ERROR_INVALID_ARG);
 
   // Check whether this is the document channel for this window (representing a
@@ -311,7 +311,6 @@ ThirdPartyUtil::GetTopWindowForChannel(nsIChannel* aChannel, nsIDOMWindow** aWin
 {
   NS_ENSURE_ARG(aWin);
 
-  nsresult rv;
   // Find the associated window and its parent window.
   nsCOMPtr<nsILoadContext> ctx;
   NS_QueryNotificationCallbacks(aChannel, ctx);
@@ -320,13 +319,15 @@ ThirdPartyUtil::GetTopWindowForChannel(nsIChannel* aChannel, nsIDOMWindow** aWin
   }
 
   nsCOMPtr<nsIDOMWindow> window;
-  rv = ctx->GetAssociatedWindow(getter_AddRefs(window));
+  ctx->GetAssociatedWindow(getter_AddRefs(window));
+  nsCOMPtr<nsPIDOMWindow> top = do_QueryInterface(window);
   if (!window) {
     return NS_ERROR_INVALID_ARG;
   }
 
-  rv = window->GetTop(aWin);
-  return rv;
+  top = top->GetTop();
+  top.forget(aWin);
+  return NS_OK;
 }
 
 // Get the base domain for aHostURI; e.g. for "www.bbc.co.uk", this would be
diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 23da14b74c7..82138cddd97 100755
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -6759,7 +6759,7 @@ nsContentUtils::GetFullscreenAncestor(nsIDocument* aDoc)
 
 /* static */
 bool
-nsContentUtils::IsInPointerLockContext(nsIDOMWindow* aWin)
+nsContentUtils::IsInPointerLockContext(nsPIDOMWindow* aWin)
 {
   if (!aWin) {
     return false;
@@ -6771,11 +6771,8 @@ nsContentUtils::IsInPointerLockContext(nsIDOMWindow* aWin)
     return false;
   }
 
-  nsCOMPtr<nsIDOMWindow> lockTop;
-  pointerLockedDoc->GetWindow()->GetScriptableTop(getter_AddRefs(lockTop));
-
-  nsCOMPtr<nsIDOMWindow> top;
-  aWin->GetScriptableTop(getter_AddRefs(top));
+  nsCOMPtr<nsPIDOMWindow> lockTop = pointerLockedDoc->GetWindow()->GetScriptableTop();
+  nsCOMPtr<nsPIDOMWindow> top = aWin->GetScriptableTop();
 
   return top == lockTop;
 }
diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
index 384bd0c8545..40c6bf915ae 100755
--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -2035,7 +2035,7 @@ class nsContentUtils
    * Returns true if aWin and the current pointer lock document
    * have common scriptable top window.
    */
-  static bool IsInPointerLockContext(nsIDOMWindow* aWin);
+  static bool IsInPointerLockContext(nsPIDOMWindow* aWin);
 
   /**
    * Returns the time limit on handling user input before
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 5d344b7feee..0479f5d5d70 100755
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -12325,18 +12325,15 @@ nsDocument::ShouldLockPointer(Element* aElement, Element* aCurrentLock,
     return false;
   }
 
-  nsCOMPtr<nsIDOMWindow> top;
-  ownerWindow->GetScriptableTop(getter_AddRefs(top));
-  nsCOMPtr<nsPIDOMWindow> piTop = do_QueryInterface(top);
-  if (!piTop || !piTop->GetExtantDoc() ||
-      piTop->GetExtantDoc()->Hidden()) {
+  nsCOMPtr<nsPIDOMWindow> top = ownerWindow->GetScriptableTop();
+  if (!top || !top->GetExtantDoc() || top->GetExtantDoc()->Hidden()) {
     NS_WARNING("ShouldLockPointer(): Top document isn't visible.");
     return false;
   }
 
   if (!aNoFocusCheck) {
     mozilla::ErrorResult rv;
-    if (!piTop->GetExtantDoc()->HasFocus(rv)) {
+    if (!top->GetExtantDoc()->HasFocus(rv)) {
       NS_WARNING("ShouldLockPointer(): Top document isn't focused.");
       return false;
     }
@@ -12899,10 +12896,7 @@ nsAutoSyncOperation::nsAutoSyncOperation(nsIDocument* aDoc)
   if (aDoc) {
     nsPIDOMWindow* win = aDoc->GetWindow();
     if (win) {
-      nsCOMPtr<nsIDOMWindow> topWindow;
-      win->GetTop(getter_AddRefs(topWindow));
-      nsCOMPtr<nsPIDOMWindow> top = do_QueryInterface(topWindow);
-      if (top) {
+      if (nsCOMPtr<nsPIDOMWindow> top = win->GetTop()) {
         nsCOMPtr<nsIDocument> doc = top->GetExtantDoc();
         MarkDocumentTreeToBeInSyncOperation(doc, &mDocuments);
       }
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index c2653ed6bd5..1fa3f609d78 100755
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -2285,7 +2285,7 @@ CreateNativeGlobalForInner(JSContext* aCx,
 
   nsGlobalWindow *top = nullptr;
   if (aNewInner->GetOuterWindow()) {
-    top = aNewInner->GetTop();
+    top = aNewInner->GetTopInternal();
   }
   JS::CompartmentOptions options;
 
@@ -2884,9 +2884,8 @@ nsGlobalWindow::SetDocShell(nsIDocShell* aDocShell)
     // window root object that will function as a chrome event
     // handler and receive all events that occur anywhere inside
     // our window.
-    nsCOMPtr<nsIDOMWindow> parentWindow;
-    GetParent(getter_AddRefs(parentWindow));
-    if (parentWindow.get() != static_cast<nsIDOMWindow*>(this)) {
+    nsCOMPtr<nsPIDOMWindow> parentWindow = GetParent();
+    if (parentWindow.get() != static_cast<nsPIDOMWindow*>(this)) {
       nsCOMPtr<nsPIDOMWindow> piWindow(do_QueryInterface(parentWindow));
       mChromeEventHandler = piWindow->GetChromeEventHandler();
     }
@@ -3023,7 +3022,7 @@ nsGlobalWindow::UpdateParentTarget()
     TryGetTabChildGlobalAsEventTarget(frameElement);
 
   if (!eventTarget) {
-    nsGlobalWindow* topWin = GetScriptableTop();
+    nsGlobalWindow* topWin = GetScriptableTopInternal();
     if (topWin) {
       frameElement = topWin->GetFrameElementInternal();
       eventTarget = TryGetTabChildGlobalAsEventTarget(frameElement);
@@ -3132,7 +3131,7 @@ nsGlobalWindow::ShouldPromptToBlockDialogs()
 {
   MOZ_ASSERT(IsOuterWindow());
 
-  nsGlobalWindow *topWindow = GetScriptableTop();
+  nsGlobalWindow *topWindow = GetScriptableTopInternal();
   if (!topWindow) {
     NS_ASSERTION(!mDocShell, "ShouldPromptToBlockDialogs() called without a top window?");
     return true;
@@ -3151,7 +3150,7 @@ nsGlobalWindow::AreDialogsEnabled()
 {
   MOZ_ASSERT(IsOuterWindow());
 
-  nsGlobalWindow *topWindow = GetScriptableTop();
+  nsGlobalWindow *topWindow = GetScriptableTopInternal();
   if (!topWindow) {
     NS_ERROR("AreDialogsEnabled() called without a top window?");
     return false;
@@ -3243,7 +3242,7 @@ nsGlobalWindow::ConfirmDialogIfNeeded()
 void
 nsGlobalWindow::DisableDialogs()
 {
-  nsGlobalWindow *topWindow = GetScriptableTop();
+  nsGlobalWindow *topWindow = GetScriptableTopInternal();
   if (!topWindow) {
     NS_ERROR("DisableDialogs() called without a top window?");
     return;
@@ -3259,7 +3258,7 @@ nsGlobalWindow::DisableDialogs()
 void
 nsGlobalWindow::EnableDialogs()
 {
-  nsGlobalWindow *topWindow = GetScriptableTop();
+  nsGlobalWindow *topWindow = GetScriptableTopInternal();
   if (!topWindow) {
     NS_ERROR("EnableDialogs() called without a top window?");
     return;
@@ -3687,15 +3686,13 @@ nsPIDOMWindow::CreatePerformanceObjectIfNeeded()
     // If we are dealing with an iframe, we will need the parent's performance
     // object (so we can add the iframe as a resource of that page).
     nsPerformance* parentPerformance = nullptr;
-    nsCOMPtr<nsIDOMWindow> parentWindow;
-    GetScriptableParent(getter_AddRefs(parentWindow));
-    nsCOMPtr<nsPIDOMWindow> parentPWindow = do_GetInterface(parentWindow);
-    if (GetOuterWindow() != parentPWindow) {
-      if (parentPWindow && !parentPWindow->IsInnerWindow()) {
-        parentPWindow = parentPWindow->GetCurrentInnerWindow();
+    nsCOMPtr<nsPIDOMWindow> parentWindow = GetScriptableParent();
+    if (GetOuterWindow() != parentWindow) {
+      if (parentWindow && !parentWindow->IsInnerWindow()) {
+        parentWindow = parentWindow->GetCurrentInnerWindow();
       }
-      if (parentPWindow) {
-        parentPerformance = parentPWindow->GetPerformance();
+      if (parentWindow) {
+        parentPerformance = parentWindow->GetPerformance();
       }
     }
     mPerformance =
@@ -3772,8 +3769,7 @@ nsPIDOMWindow::GetAudioGlobalVolume()
 
     globalVolume *= window->GetAudioVolume();
 
-    nsCOMPtr<nsIDOMWindow> win;
-    window->GetParent(getter_AddRefs(win));
+    nsCOMPtr<nsPIDOMWindow> win = window->GetParent();
     if (window == win) {
       break;
     }
@@ -3827,9 +3823,9 @@ nsGlobalWindow::GetSpeechSynthesis(ErrorResult& aError)
 #endif
 
 already_AddRefed<nsIDOMWindow>
-nsGlobalWindow::GetParent(ErrorResult& aError)
+nsGlobalWindow::GetParentOuter()
 {
-  FORWARD_TO_OUTER_OR_THROW(GetParent, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsOuterWindow());
 
   if (!mDocShell) {
     return nullptr;
@@ -3839,12 +3835,18 @@ nsGlobalWindow::GetParent(ErrorResult& aError)
   if (mDocShell->GetIsBrowserOrApp()) {
     parent = this;
   } else {
-    aError = GetRealParent(getter_AddRefs(parent));
+    parent = GetParent();
   }
 
   return parent.forget();
 }
 
+already_AddRefed<nsIDOMWindow>
+nsGlobalWindow::GetParent(ErrorResult& aError)
+{
+  FORWARD_TO_OUTER_OR_THROW(GetParentOuter, (), aError, nullptr);
+}
+
 /**
  * GetScriptableParent is called when script reads window.parent.
  *
@@ -3852,28 +3854,27 @@ nsGlobalWindow::GetParent(ErrorResult& aError)
  * mozbrowser> boundaries, so if |this| is contained by an <iframe
  * mozbrowser>, we will return |this| as its own parent.
  */
-NS_IMETHODIMP
-nsGlobalWindow::GetScriptableParent(nsIDOMWindow** aParent)
+nsPIDOMWindow*
+nsGlobalWindow::GetScriptableParent()
 {
-  ErrorResult rv;
-  nsCOMPtr<nsIDOMWindow> parent = GetParent(rv);
-  parent.forget(aParent);
+  FORWARD_TO_OUTER(GetScriptableParent, (), nullptr);
 
-  return rv.ErrorCode();
+  nsCOMPtr<nsIDOMWindow> parent = GetParentOuter();
+  nsCOMPtr<nsPIDOMWindow> piParent = do_QueryInterface(parent);
+  return piParent.get();
 }
 
 /**
  * nsIDOMWindow::GetParent (when called from C++) is just a wrapper around
  * GetRealParent.
  */
-NS_IMETHODIMP
-nsGlobalWindow::GetRealParent(nsIDOMWindow** aParent)
+already_AddRefed<nsPIDOMWindow>
+nsGlobalWindow::GetParent()
 {
-  FORWARD_TO_OUTER(GetRealParent, (aParent), NS_ERROR_NOT_INITIALIZED);
+  MOZ_ASSERT(IsOuterWindow());
 
-  *aParent = nullptr;
   if (!mDocShell) {
-    return NS_OK;
+    return nullptr;
   }
 
   nsCOMPtr<nsIDocShell> parent;
@@ -3881,24 +3882,22 @@ nsGlobalWindow::GetRealParent(nsIDOMWindow** aParent)
 
   if (parent) {
     nsCOMPtr<nsPIDOMWindow> win = parent->GetWindow();
-    win.forget(aParent);
-  }
-  else {
-    *aParent = static_cast<nsIDOMWindow*>(this);
-    NS_ADDREF(*aParent);
+    return win.forget();
   }
-  return NS_OK;
+
+  nsCOMPtr<nsPIDOMWindow> win(this);
+  return win.forget();
 }
 
 static nsresult
-GetTopImpl(nsGlobalWindow* aWin, nsIDOMWindow** aTop, bool aScriptable)
+GetTopImpl(nsGlobalWindow* aWin, nsPIDOMWindow** aTop, bool aScriptable)
 {
   *aTop = nullptr;
 
   // Walk up the parent chain.
 
-  nsCOMPtr<nsIDOMWindow> prevParent = aWin;
-  nsCOMPtr<nsIDOMWindow> parent = aWin;
+  nsCOMPtr<nsPIDOMWindow> prevParent = aWin;
+  nsCOMPtr<nsPIDOMWindow> parent = aWin;
   do {
     if (!parent) {
       break;
@@ -3906,15 +3905,14 @@ GetTopImpl(nsGlobalWindow* aWin, nsIDOMWindow** aTop, bool aScriptable)
 
     prevParent = parent;
 
-    nsCOMPtr<nsIDOMWindow> newParent;
+    nsCOMPtr<nsPIDOMWindow> newParent;
     nsresult rv;
     if (aScriptable) {
-      rv = parent->GetScriptableParent(getter_AddRefs(newParent));
+      newParent = parent->GetScriptableParent();
     }
     else {
-      rv = parent->GetParent(getter_AddRefs(newParent));
+      newParent = parent->GetParent();
     }
-    NS_ENSURE_SUCCESS(rv, rv);
 
     parent = newParent;
 
@@ -3934,31 +3932,23 @@ GetTopImpl(nsGlobalWindow* aWin, nsIDOMWindow** aTop, bool aScriptable)
  * boundaries.  If we encounter a window owned by an <iframe mozbrowser> while
  * walking up the window hierarchy, we'll stop and return that window.
  */
-NS_IMETHODIMP
-nsGlobalWindow::GetScriptableTop(nsIDOMWindow **aTop)
+nsPIDOMWindow*
+nsGlobalWindow::GetScriptableTop()
 {
-  FORWARD_TO_OUTER(GetScriptableTop, (aTop), NS_ERROR_NOT_INITIALIZED);
-  return GetTopImpl(this, aTop, /* aScriptable = */ true);
+  FORWARD_TO_OUTER(GetScriptableTop, (), nullptr);
+  nsCOMPtr<nsPIDOMWindow> window;
+  GetTopImpl(this, getter_AddRefs(window), /* aScriptable = */ true);
+  return window.get();
 }
 
-/**
- * nsIDOMWindow::GetTop (when called from C++) is just a wrapper around
- * GetRealTop.
- */
-NS_IMETHODIMP
-nsGlobalWindow::GetRealTop(nsIDOMWindow** aTop)
+
+already_AddRefed<nsPIDOMWindow>
+nsGlobalWindow::GetTop()
 {
-  nsGlobalWindow* outer;
-  if (IsInnerWindow()) {
-    outer = GetOuterWindowInternal();
-    if (!outer) {
-      NS_WARNING("No outer window available!");
-      return NS_ERROR_NOT_INITIALIZED;
-    }
-  } else {
-    outer = this;
-  }
-  return GetTopImpl(outer, aTop, /* aScriptable = */ false);
+  MOZ_ASSERT(IsOuterWindow());
+  nsCOMPtr<nsPIDOMWindow> window;
+  GetTopImpl(this, getter_AddRefs(window), /* aScriptable = */ false);
+  return window.forget();
 }
 
 void
@@ -4001,7 +3991,7 @@ nsGlobalWindow::GetContentInternal(ErrorResult& aError)
   // If we're contained in <iframe mozbrowser> or <iframe mozapp>, then
   // GetContent is the same as window.top.
   if (mDocShell && mDocShell->GetIsInBrowserOrApp()) {
-    return GetTop(aError);
+    return GetTopOuter();
   }
 
   nsCOMPtr<nsIDocShellTreeItem> primaryContent;
@@ -4496,7 +4486,7 @@ nsGlobalWindow::GetControllers(nsIControllers** aResult)
   return rv.ErrorCode();
 }
 
-nsIDOMWindow*
+nsPIDOMWindow*
 nsGlobalWindow::GetOpenerWindow(ErrorResult& aError)
 {
   FORWARD_TO_OUTER_OR_THROW(GetOpenerWindow, (aError), aError, nullptr);
@@ -5846,6 +5836,21 @@ nsGlobalWindow::GetLength(uint32_t* aLength)
   return NS_OK;
 }
 
+already_AddRefed<nsIDOMWindow>
+nsGlobalWindow::GetTopOuter()
+{
+  MOZ_ASSERT(IsOuterWindow());
+
+  nsCOMPtr<nsPIDOMWindow> top = GetScriptableTop();
+  return top.forget();
+}
+
+already_AddRefed<nsIDOMWindow>
+nsGlobalWindow::GetTop(mozilla::ErrorResult& aError)
+{
+  FORWARD_TO_OUTER_OR_THROW(GetTopOuter, (), aError, nullptr);
+}
+
 nsPIDOMWindow*
 nsGlobalWindow::GetChildWindow(const nsAString& aName)
 {
@@ -7564,17 +7569,13 @@ nsGlobalWindow::PopupWhitelisted()
   if (!IsPopupBlocked(mDoc))
     return true;
 
-  nsCOMPtr<nsIDOMWindow> parent;
-
-  if (NS_FAILED(GetParent(getter_AddRefs(parent))) ||
-      parent == static_cast<nsIDOMWindow*>(this))
+  nsCOMPtr<nsPIDOMWindow> parent = GetParent();
+  if (parent == static_cast<nsPIDOMWindow*>(this))
   {
     return false;
   }
 
-  return static_cast<nsGlobalWindow*>
-                    (static_cast<nsIDOMWindow*>
-                                (parent.get()))->PopupWhitelisted();
+  return static_cast<nsGlobalWindow*>(parent.get())->PopupWhitelisted();
 }
 
 /*
@@ -7624,9 +7625,7 @@ nsGlobalWindow::FireAbuseEvents(const nsAString &aPopupURL,
 {
   // fetch the URI of the window requesting the opened window
 
-  nsCOMPtr<nsIDOMWindow> topWindow;
-  GetTop(getter_AddRefs(topWindow));
-  nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(topWindow);
+  nsCOMPtr<nsPIDOMWindow> window = GetTop();
   if (!window) {
     return;
   }
@@ -8706,7 +8705,7 @@ nsGlobalWindow::EnterModalState()
 
   // GetScriptableTop, not GetTop, so that EnterModalState works properly with
   // <iframe mozbrowser>.
-  nsGlobalWindow* topWin = GetScriptableTop();
+  nsGlobalWindow* topWin = GetScriptableTopInternal();
 
   if (!topWin) {
     NS_ERROR("Uh, EnterModalState() called w/o a reachable top window?");
@@ -8837,7 +8836,7 @@ nsGlobalWindow::LeaveModalState()
 {
   MOZ_ASSERT(IsOuterWindow(), "Modal state is maintained on outer windows");
 
-  nsGlobalWindow* topWin = GetScriptableTop();
+  nsGlobalWindow* topWin = GetScriptableTopInternal();
 
   if (!topWin) {
     NS_ERROR("Uh, LeaveModalState() called w/o a reachable top window?");
@@ -8878,7 +8877,7 @@ nsGlobalWindow::LeaveModalState()
 bool
 nsGlobalWindow::IsInModalState()
 {
-  nsGlobalWindow *topWin = GetScriptableTop();
+  nsGlobalWindow *topWin = GetScriptableTopInternal();
 
   if (!topWin) {
     NS_ERROR("Uh, IsInModalState() called w/o a reachable top window?");
@@ -9860,10 +9859,9 @@ nsGlobalWindow::GetPrivateParent()
 {
   MOZ_ASSERT(IsOuterWindow());
 
-  nsCOMPtr<nsIDOMWindow> parent;
-  GetParent(getter_AddRefs(parent));
+  nsCOMPtr<nsPIDOMWindow> parent = GetParent();
 
-  if (static_cast<nsIDOMWindow *>(this) == parent.get()) {
+  if (static_cast<nsPIDOMWindow *>(this) == parent.get()) {
     nsCOMPtr<nsIContent> chromeElement(do_QueryInterface(mChromeEventHandler));
     if (!chromeElement)
       return nullptr;             // This is ok, just means a null parent.
@@ -9895,16 +9893,15 @@ nsGlobalWindow::GetPrivateRoot()
     return outer->GetPrivateRoot();
   }
 
-  nsCOMPtr<nsIDOMWindow> top;
-  GetTop(getter_AddRefs(top));
+  nsCOMPtr<nsPIDOMWindow> top = GetTop();
 
   nsCOMPtr<nsIContent> chromeElement(do_QueryInterface(mChromeEventHandler));
   if (chromeElement) {
     nsIDocument* doc = chromeElement->GetComposedDoc();
     if (doc) {
-      nsIDOMWindow *parent = doc->GetWindow();
+      nsCOMPtr<nsPIDOMWindow> parent = doc->GetWindow();
       if (parent) {
-        parent->GetTop(getter_AddRefs(top));
+        top = parent->GetTop();
       }
     }
   }
@@ -11850,10 +11847,9 @@ nsGlobalWindow::GetParentInternal()
     return outer->GetParentInternal();
   }
 
-  nsCOMPtr<nsIDOMWindow> parent;
-  GetParent(getter_AddRefs(parent));
+  nsCOMPtr<nsPIDOMWindow> parent = GetParent();
 
-  if (parent && parent != static_cast<nsIDOMWindow *>(this)) {
+  if (parent && parent != static_cast<nsPIDOMWindow *>(this)) {
     return parent;
   }
 
diff --git a/dom/base/nsGlobalWindow.h b/dom/base/nsGlobalWindow.h
index 4515f0844b5..ddaa6532a0b 100755
--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -402,7 +402,7 @@ class nsGlobalWindow : public mozilla::dom::EventTarget,
                                 bool aUseCapture,
                                 const mozilla::dom::Nullable<bool>& aWantsUntrusted,
                                 mozilla::ErrorResult& aRv) override;
-  virtual nsIDOMWindow* GetOwnerGlobalForBindings() override
+  virtual nsPIDOMWindow* GetOwnerGlobalForBindings() override
   {
     if (IsOuterWindow()) {
       return this;
@@ -525,30 +525,22 @@ class nsGlobalWindow : public mozilla::dom::EventTarget,
     return FromSupports(wrapper->Native());
   }
 
-  /**
-   * Wrap nsIDOMWindow::GetTop so we can overload the inline GetTop()
-   * implementation below.  (nsIDOMWindow::GetTop simply calls
-   * nsIDOMWindow::GetRealTop().)
-   */
-  nsresult GetTop(nsIDOMWindow **aWindow)
+  already_AddRefed<nsIDOMWindow> GetTopOuter();
+  already_AddRefed<nsPIDOMWindow> GetTop() override;
+  nsPIDOMWindow* GetScriptableTop() override;
+  inline nsGlobalWindow *GetTopInternal()
   {
-    return nsIDOMWindow::GetTop(aWindow);
-  }
-
-  inline nsGlobalWindow *GetTop()
-  {
-    nsCOMPtr<nsIDOMWindow> top;
-    GetTop(getter_AddRefs(top));
+    nsGlobalWindow* outer = IsOuterWindow() ? this : GetOuterWindowInternal();
+    nsCOMPtr<nsPIDOMWindow> top = outer ? outer->GetTop() : nullptr;
     if (top)
       return static_cast<nsGlobalWindow *>(top.get());
     return nullptr;
   }
 
-  inline nsGlobalWindow* GetScriptableTop()
+  inline nsGlobalWindow* GetScriptableTopInternal()
   {
-    nsCOMPtr<nsIDOMWindow> top;
-    GetScriptableTop(getter_AddRefs(top));
-    return static_cast<nsGlobalWindow *>(top.get());
+    nsPIDOMWindow* top = GetScriptableTop();
+    return static_cast<nsGlobalWindow*>(top);
   }
 
   nsPIDOMWindow* GetChildWindow(const nsAString& aName);
@@ -848,15 +840,10 @@ class nsGlobalWindow : public mozilla::dom::EventTarget,
   void Blur(mozilla::ErrorResult& aError);
   already_AddRefed<nsIDOMWindow> GetFrames(mozilla::ErrorResult& aError);
   uint32_t Length();
-  already_AddRefed<nsIDOMWindow> GetTop(mozilla::ErrorResult& aError)
-  {
-    nsCOMPtr<nsIDOMWindow> top;
-    aError = GetScriptableTop(getter_AddRefs(top));
-    return top.forget();
-  }
+  already_AddRefed<nsIDOMWindow> GetTop(mozilla::ErrorResult& aError);
 protected:
   explicit nsGlobalWindow(nsGlobalWindow *aOuterWindow);
-  nsIDOMWindow* GetOpenerWindow(mozilla::ErrorResult& aError);
+  nsPIDOMWindow* GetOpenerWindow(mozilla::ErrorResult& aError);
   // Initializes the mWasOffline member variable
   void InitWasOffline();
 public:
@@ -864,8 +851,10 @@ class nsGlobalWindow : public mozilla::dom::EventTarget,
                  mozilla::ErrorResult& aError);
   void SetOpener(JSContext* aCx, JS::Handle<JS::Value> aOpener,
                  mozilla::ErrorResult& aError);
-  using nsIDOMWindow::GetParent;
+  already_AddRefed<nsIDOMWindow> GetParentOuter();
   already_AddRefed<nsIDOMWindow> GetParent(mozilla::ErrorResult& aError);
+  already_AddRefed<nsPIDOMWindow> GetParent() override;
+  nsPIDOMWindow* GetScriptableParent() override;
   mozilla::dom::Element* GetFrameElement(mozilla::ErrorResult& aError);
   already_AddRefed<nsIDOMWindow> Open(const nsAString& aUrl,
                                       const nsAString& aName,
@@ -873,9 +862,9 @@ class nsGlobalWindow : public mozilla::dom::EventTarget,
                                       mozilla::ErrorResult& aError);
   nsresult Open(const nsAString& aUrl, const nsAString& aName,
                 const nsAString& aOptions,
-		nsIDocShellLoadInfo* aLoadInfo,
-		bool aForceNoOpener,
-		nsPIDOMWindow **_retval) override;
+                nsIDocShellLoadInfo* aLoadInfo,
+     	          bool aForceNoOpener,
+                nsPIDOMWindow **_retval) override;
   mozilla::dom::Navigator* GetNavigator(mozilla::ErrorResult& aError);
   nsIDOMOfflineResourceList* GetApplicationCache(mozilla::ErrorResult& aError);
 
@@ -1231,8 +1220,8 @@ class nsGlobalWindow : public mozilla::dom::EventTarget,
                                     bool aNavigate,
                                     nsIArray *argv,
                                     nsISupports *aExtraArgument,
-				    nsIDocShellLoadInfo* aLoadInfo,
-				    bool aForceNoOpener,
+				                            nsIDocShellLoadInfo* aLoadInfo,
+				                            bool aForceNoOpener,
                                     nsIPrincipal *aCalleePrincipal,
                                     JSContext *aJSCallerContext,
                                     nsIDOMWindow **aReturn);
diff --git a/dom/base/nsObjectLoadingContent.cpp b/dom/base/nsObjectLoadingContent.cpp
index f3dba17f7c7..d5ad6b223ce 100755
--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -3378,17 +3378,14 @@ nsObjectLoadingContent::ShouldPlay(FallbackType &aReason, bool aIgnoreCurrentTyp
   MOZ_ASSERT(thisContent);
   nsIDocument* ownerDoc = thisContent->OwnerDoc();
 
-  nsCOMPtr<nsIDOMWindow> window = ownerDoc->GetWindow();
+  nsCOMPtr<nsPIDOMWindow> window = ownerDoc->GetWindow();
   if (!window) {
     return false;
   }
-  nsCOMPtr<nsIDOMWindow> topWindow;
-  rv = window->GetTop(getter_AddRefs(topWindow));
-  NS_ENSURE_SUCCESS(rv, false);
-  nsCOMPtr<nsIDOMDocument> topDocument;
-  rv = topWindow->GetDocument(getter_AddRefs(topDocument));
-  NS_ENSURE_SUCCESS(rv, false);
-  nsCOMPtr<nsIDocument> topDoc = do_QueryInterface(topDocument);
+  nsCOMPtr<nsPIDOMWindow> topWindow = window->GetTop();
+  NS_ENSURE_TRUE(topWindow, false);
+  nsCOMPtr<nsIDocument> topDoc = topWindow->GetDoc();
+  NS_ENSURE_TRUE(topDoc, false);
 
   nsCOMPtr<nsIPermissionManager> permissionManager = services::GetPermissionManager();
   NS_ENSURE_TRUE(permissionManager, false);
diff --git a/dom/base/nsPIDOMWindow.h b/dom/base/nsPIDOMWindow.h
index 2db79b23432..d1ba515f7a4 100755
--- a/dom/base/nsPIDOMWindow.h
+++ b/dom/base/nsPIDOMWindow.h
@@ -78,6 +78,23 @@ class nsPIDOMWindow : public nsIDOMWindowInternal
   virtual void ActivateOrDeactivate(bool aActivate) = 0;
 
   // this is called GetTopWindowRoot to avoid conflicts with nsIDOMWindow::GetWindowRoot
+  /**
+   * |top| gets the root of the window hierarchy.
+   *
+   * This function does not cross chrome-content boundaries, so if this
+   * window's parent is of a different type, |top| will return this window.
+   *
+   * When script reads the top property, we run GetScriptableTop, which
+   * will not cross an <iframe mozbrowser> boundary.
+   *
+   * In contrast, C++ calls to GetTop are forwarded to GetRealTop, which
+   * ignores <iframe mozbrowser> boundaries.
+   */
+
+  virtual already_AddRefed<nsPIDOMWindow> GetTop() = 0; // Outer only
+  virtual already_AddRefed<nsPIDOMWindow> GetParent() = 0;
+  virtual nsPIDOMWindow* GetScriptableTop() = 0;
+  virtual nsPIDOMWindow* GetScriptableParent() = 0;
   virtual already_AddRefed<nsPIWindowRoot> GetTopWindowRoot() = 0;
 
   // Inner windows only.
diff --git a/dom/base/nsWindowMemoryReporter.cpp b/dom/base/nsWindowMemoryReporter.cpp
index a5507e24a67..6ab2f3b95d3 100755
--- a/dom/base/nsWindowMemoryReporter.cpp
+++ b/dom/base/nsWindowMemoryReporter.cpp
@@ -253,7 +253,7 @@ CollectWindowReports(nsGlobalWindow *aWindow,
   if (aWindow->GetOuterWindow()) {
     // Our window should have a null top iff it has a null docshell.
     MOZ_ASSERT(!!aWindow->GetTop() == !!aWindow->GetDocShell());
-    top = aWindow->GetTop();
+    top = aWindow->GetTopInternal();
     if (top) {
       location = GetWindowURI(top);
     }
@@ -763,7 +763,7 @@ CheckForGhostWindowsEnumerator(nsISupports *aKey, TimeStamp& aTimeStamp,
   // overflow.
   nsCOMPtr<nsIDOMWindow> top;
   if (window->GetOuterWindow()) {
-    window->GetTop(getter_AddRefs(top));
+    top = window->GetOuterWindow()->GetTop();
   }
 
   if (top) {
@@ -820,7 +820,7 @@ GetNonDetachedWindowDomainsEnumerator(const uint64_t& aId, nsGlobalWindow* aWind
 
   // Null outer window implies null top, but calling GetTop() when there's no
   // outer window causes us to spew debug warnings.
-  if (!aWindow->GetOuterWindow() || !aWindow->GetTop()) {
+  if (!aWindow->GetOuterWindow() || !aWindow->GetTopInternal()) {
     // This window is detached, so we don't care about its domain.
     return PL_DHASH_NEXT;
   }
diff --git a/dom/base/nsXMLHttpRequest.cpp b/dom/base/nsXMLHttpRequest.cpp
index 2cd4760dbb3..f9dee0c04fc 100755
--- a/dom/base/nsXMLHttpRequest.cpp
+++ b/dom/base/nsXMLHttpRequest.cpp
@@ -3099,8 +3099,7 @@ nsXMLHttpRequest::Send(nsIVariant* aVariant, const Nullable<RequestBody>& aBody)
     nsCOMPtr<nsIDocument> suspendedDoc;
     nsCOMPtr<nsIRunnable> resumeTimeoutRunnable;
     if (GetOwner()) {
-      nsCOMPtr<nsIDOMWindow> topWindow;
-      if (NS_SUCCEEDED(GetOwner()->GetTop(getter_AddRefs(topWindow)))) {
+      if (nsCOMPtr<nsPIDOMWindow> topWindow = GetOwner()->GetOuterWindow()->GetTop()) {
         nsCOMPtr<nsPIDOMWindow> suspendedWindow(do_QueryInterface(topWindow));
         if (suspendedWindow &&
             (suspendedWindow = suspendedWindow->GetCurrentInnerWindow())) {
diff --git a/dom/browser-element/BrowserElementParent.cpp b/dom/browser-element/BrowserElementParent.cpp
index 83f5057ba4d..5140d3252e0 100755
--- a/dom/browser-element/BrowserElementParent.cpp
+++ b/dom/browser-element/BrowserElementParent.cpp
@@ -260,10 +260,8 @@ BrowserElementParent::OpenWindowInProcess(nsIDOMWindow* aOpenerWindow,
   // GetScriptableTop gets us the <iframe mozbrowser>'s window; we'll use its
   // frame element, rather than aOpenerWindow's frame element, as our "opener
   // frame element" below.
-  nsCOMPtr<nsIDOMWindow> topWindow;
-  aOpenerWindow->GetScriptableTop(getter_AddRefs(topWindow));
-
-  nsCOMPtr<nsPIDOMWindow> win = do_QueryInterface(topWindow);
+  nsCOMPtr<nsPIDOMWindow> openerWindow = do_QueryInterface(aOpenerWindow);
+  nsCOMPtr<nsPIDOMWindow> win = openerWindow->GetScriptableTop();
 
   nsCOMPtr<Element> openerFrameElement = win->GetFrameElementInternal();
   NS_ENSURE_TRUE(openerFrameElement, BrowserElementParent::OPEN_WINDOW_IGNORED);
diff --git a/dom/events/EventStateManager.cpp b/dom/events/EventStateManager.cpp
index 1d9cc6dbfcf..f4bab24d705 100755
--- a/dom/events/EventStateManager.cpp
+++ b/dom/events/EventStateManager.cpp
@@ -2950,17 +2950,17 @@ EventStateManager::PostHandleEvent(nsPresContext* aPresContext,
         EnsureDocument(mPresContext);
         nsIFocusManager* fm = nsFocusManager::GetFocusManager();
         if (mDocument && fm) {
-          nsCOMPtr<nsIDOMWindow> currentWindow;
-          fm->GetFocusedWindow(getter_AddRefs(currentWindow));
+          nsCOMPtr<nsIDOMWindow> window;
+          fm->GetFocusedWindow(getter_AddRefs(window));
+          nsCOMPtr<nsPIDOMWindow> currentWindow = do_QueryInterface(window);
           if (currentWindow && mDocument->GetWindow() &&
               currentWindow != mDocument->GetWindow() &&
               !nsContentUtils::IsChromeDoc(mDocument)) {
-            nsCOMPtr<nsIDOMWindow> currentTop;
-            nsCOMPtr<nsIDOMWindow> newTop;
-            currentWindow->GetTop(getter_AddRefs(currentTop));
-            mDocument->GetWindow()->GetTop(getter_AddRefs(newTop));
-            nsCOMPtr<nsPIDOMWindow> win = do_QueryInterface(currentWindow);
-            nsCOMPtr<nsIDocument> currentDoc = win->GetExtantDoc();
+            nsCOMPtr<nsPIDOMWindow> currentTop;
+            nsCOMPtr<nsPIDOMWindow> newTop;
+            currentTop = currentWindow->GetTop();
+            newTop = mDocument->GetWindow()->GetTop();
+            nsCOMPtr<nsIDocument> currentDoc = currentWindow->GetExtantDoc();
             if (nsContentUtils::IsChromeDoc(currentDoc) ||
                 (currentTop && newTop && currentTop != newTop)) {
               fm->SetFocusedWindow(mDocument->GetWindow());
diff --git a/dom/html/nsGenericHTMLElement.cpp b/dom/html/nsGenericHTMLElement.cpp
index 2b32dec16ba..092598cb98c 100755
--- a/dom/html/nsGenericHTMLElement.cpp
+++ b/dom/html/nsGenericHTMLElement.cpp
@@ -135,10 +135,8 @@ class nsAutoFocusEvent : public nsRunnable
     }
 
     // Trying to found the top window (equivalent to window.top).
-    nsCOMPtr<nsIDOMWindow> top;
-    window->GetTop(getter_AddRefs(top));
-    if (top) {
-      window = static_cast<nsPIDOMWindow*>(top.get());
+    if (nsCOMPtr<nsPIDOMWindow> top = window->GetTop()) {
+      window = top;
     }
 
     if (window->GetFocusedNode()) {
diff --git a/dom/interfaces/base/nsIDOMWindow.idl b/dom/interfaces/base/nsIDOMWindow.idl
index 9d3d44789bd..49c4ef454f1 100755
--- a/dom/interfaces/base/nsIDOMWindow.idl
+++ b/dom/interfaces/base/nsIDOMWindow.idl
@@ -92,63 +92,6 @@ interface nsIDOMWindow : nsISupports
   /* [replaceable] length */
   readonly attribute unsigned long                      length;
 
-  /**
-   * |top| gets the root of the window hierarchy.
-   *
-   * This function does not cross chrome-content boundaries, so if this
-   * window's parent is of a different type, |top| will return this window.
-   *
-   * When script reads the top property, we run GetScriptableTop, which
-   * will not cross an <iframe mozbrowser> boundary.
-   *
-   * In contrast, C++ calls to GetTop are forwarded to GetRealTop, which
-   * ignores <iframe mozbrowser> boundaries.
-   *
-   * This property is "replaceable" in JavaScript.
-   */
-  [binaryname(ScriptableTop)]
-  readonly attribute nsIDOMWindow                       top;
-
-  /**
-   * You shouldn't need to call this function directly; call GetTop instead.
-   */
-  [noscript]
-  readonly attribute nsIDOMWindow                       realTop;
-
-  %{C++
-  nsresult GetTop(nsIDOMWindow **aWindow)
-  {
-    return GetRealTop(aWindow);
-  }
-  %}
-
-  /**
-   * |parent| gets this window's parent window.  If this window has no parent,
-   * we return the window itself.
-   *
-   * This property does not cross chrome-content boundaries, so if this
-   * window's parent is of a different type, we return the window itself as its
-   * parent.
-   *
-   * When script reads the property (or when C++ calls ScriptableTop), this
-   * property does not cross <iframe mozbrowser> boundaries.  In contrast, when
-   * C++ calls GetParent, we ignore the mozbrowser attribute.
-   */
-  [binaryname(ScriptableParent)]
-  readonly attribute nsIDOMWindow                       parent;
-
-  /**
-   * You shouldn't need to read this property directly; call GetParent instead.
-   */
-  [noscript]
-  readonly attribute nsIDOMWindow                       realParent;
-
-  %{C++
-  inline nsresult GetParent(nsIDOMWindow **aWindow)
-  {
-    return GetRealParent(aWindow);
-  }
-  %}
 
   [implicit_jscontext, binaryname(ScriptableOpener)]
            attribute jsval                              opener;
diff --git a/dom/plugins/base/nsPluginInstanceOwner.cpp b/dom/plugins/base/nsPluginInstanceOwner.cpp
index dc056d996a7..426d9bde3cd 100755
--- a/dom/plugins/base/nsPluginInstanceOwner.cpp
+++ b/dom/plugins/base/nsPluginInstanceOwner.cpp
@@ -2891,11 +2891,8 @@ NS_IMETHODIMP nsPluginInstanceOwner::CreateWidget(void)
 #ifndef XP_MACOSX
       // If we're running in the content process, we need a remote widget created in chrome.
       if (XRE_GetProcessType() == GoannaProcessType_Content) {
-        nsCOMPtr<nsIDOMWindow> window = doc->GetWindow();
-        if (window) {
-          nsCOMPtr<nsIDOMWindow> topWindow;
-          window->GetTop(getter_AddRefs(topWindow));
-          if (topWindow) {
+        if (nsCOMPtr<nsPIDOMWindow> window = doc->GetWindow()) {
+          if (nsCOMPtr<nsIDOMWindow> topWindow = window->GetTop()) {
             dom::TabChild* tc = dom::TabChild::GetFrom(topWindow);
             if (tc) {
               // This returns a PluginWidgetProxy which remotes a number of calls.
diff --git a/uriloader/base/nsDocLoader.cpp b/uriloader/base/nsDocLoader.cpp
index 8a0e77735ae..5540c7e40c1 100755
--- a/uriloader/base/nsDocLoader.cpp
+++ b/uriloader/base/nsDocLoader.cpp
@@ -918,10 +918,7 @@ nsDocLoader::GetIsTopLevel(bool *aResult)
     nsCOMPtr<nsPIDOMWindow> piwindow = do_QueryInterface(window);
     NS_ENSURE_STATE(piwindow);
 
-    nsCOMPtr<nsIDOMWindow> topWindow;
-    nsresult rv = piwindow->GetTop(getter_AddRefs(topWindow));
-    NS_ENSURE_SUCCESS(rv, rv);
-
+    nsCOMPtr<nsPIDOMWindow> topWindow = piwindow->GetTop();
     *aResult = piwindow == topWindow;
   }