--- a/accessible/android/DocAccessibleWrap.cpp
+++ b/accessible/android/DocAccessibleWrap.cpp
@@ -17,17 +17,17 @@
 using namespace mozilla::a11y;
 
 const uint32_t kCacheRefreshInterval = 500;
 
 ////////////////////////////////////////////////////////////////////////////////
 // DocAccessibleWrap
 ////////////////////////////////////////////////////////////////////////////////
 
-DocAccessibleWrap::DocAccessibleWrap(nsIDocument* aDocument,
+DocAccessibleWrap::DocAccessibleWrap(Document* aDocument,
                                      nsIPresShell* aPresShell)
     : DocAccessible(aDocument, aPresShell) {
   nsCOMPtr<nsIDocShellTreeItem> treeItem(aDocument->GetDocShell());
 
   nsCOMPtr<nsIDocShellTreeItem> parentTreeItem;
   treeItem->GetParent(getter_AddRefs(parentTreeItem));
 
   if (treeItem->ItemType() == nsIDocShellTreeItem::typeContent &&

--- a/accessible/android/DocAccessibleWrap.h
+++ b/accessible/android/DocAccessibleWrap.h
@@ -9,17 +9,17 @@
 #include "DocAccessible.h"
 #include "nsITimer.h"
 
 namespace mozilla {
 namespace a11y {
 
 class DocAccessibleWrap : public DocAccessible {
  public:
-  DocAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  DocAccessibleWrap(Document* aDocument, nsIPresShell* aPresShell);
   virtual ~DocAccessibleWrap();
 
   virtual nsresult HandleAccEvent(AccEvent* aEvent) override;
 
   /**
    * Manage the mapping from id to Accessible.
    */
   void AddID(uint32_t aID, AccessibleWrap* aAcc) {

--- a/accessible/android/RootAccessibleWrap.cpp
+++ b/accessible/android/RootAccessibleWrap.cpp
@@ -8,17 +8,17 @@
 #include "Accessible-inl.h"
 #include "AccessibleOrProxy.h"
 #include "DocAccessibleParent.h"
 #include "ProxyAccessibleWrap.h"
 #include "SessionAccessibility.h"
 
 using namespace mozilla::a11y;
 
-RootAccessibleWrap::RootAccessibleWrap(nsIDocument* aDoc,
+RootAccessibleWrap::RootAccessibleWrap(mozilla::dom::Document* aDoc,
                                        nsIPresShell* aPresShell)
     : RootAccessible(aDoc, aPresShell) {}
 
 RootAccessibleWrap::~RootAccessibleWrap() {}
 
 AccessibleWrap* RootAccessibleWrap::GetContentAccessible() {
   if (ProxyAccessible* proxy = GetPrimaryRemoteTopLevelContentDoc()) {
     return WrapperFor(proxy);

--- a/accessible/android/RootAccessibleWrap.h
+++ b/accessible/android/RootAccessibleWrap.h
@@ -10,17 +10,17 @@
 
 namespace mozilla {
 namespace a11y {
 
 class DocProxyAccessibleWrap;
 
 class RootAccessibleWrap : public RootAccessible {
  public:
-  RootAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  RootAccessibleWrap(dom::Document* aDocument, nsIPresShell* aPresShell);
   virtual ~RootAccessibleWrap();
 
   AccessibleWrap* GetContentAccessible();
 
   AccessibleWrap* FindAccessibleById(int32_t aID);
 
   // Recursively searches for the accessible ID within the document tree.
   AccessibleWrap* FindAccessibleById(DocAccessibleWrap* aDocument, int32_t aID);

--- a/accessible/atk/DocAccessibleWrap.cpp
+++ b/accessible/atk/DocAccessibleWrap.cpp
@@ -8,13 +8,13 @@
 #include "DocAccessibleWrap.h"
 
 using namespace mozilla::a11y;
 
 ////////////////////////////////////////////////////////////////////////////////
 // DocAccessibleWrap
 ////////////////////////////////////////////////////////////////////////////////
 
-DocAccessibleWrap::DocAccessibleWrap(nsIDocument* aDocument,
+DocAccessibleWrap::DocAccessibleWrap(dom::Document* aDocument,
                                      nsIPresShell* aPresShell)
     : DocAccessible(aDocument, aPresShell), mActivated(false) {}
 
 DocAccessibleWrap::~DocAccessibleWrap() {}

--- a/accessible/atk/DocAccessibleWrap.h
+++ b/accessible/atk/DocAccessibleWrap.h
@@ -13,17 +13,17 @@
 
 #include "DocAccessible.h"
 
 namespace mozilla {
 namespace a11y {
 
 class DocAccessibleWrap : public DocAccessible {
  public:
-  DocAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  DocAccessibleWrap(dom::Document* aDocument, nsIPresShell* aPresShell);
   virtual ~DocAccessibleWrap();
 
   bool mActivated;
 };
 
 }  // namespace a11y
 }  // namespace mozilla
 

--- a/accessible/base/DocManager.cpp
+++ b/accessible/base/DocManager.cpp
@@ -47,17 +47,17 @@ nsRefPtrHashtable<nsPtrHashKey<const Doc
 // DocManager
 ////////////////////////////////////////////////////////////////////////////////
 
 DocManager::DocManager() : mDocAccessibleCache(2), mXPCDocumentCache(0) {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // DocManager public
 
-DocAccessible* DocManager::GetDocAccessible(nsIDocument* aDocument) {
+DocAccessible* DocManager::GetDocAccessible(Document* aDocument) {
   if (!aDocument) return nullptr;
 
   DocAccessible* docAcc = GetExistingDocAccessible(aDocument);
   if (docAcc) return docAcc;
 
   return CreateDocOrRootAccessible(aDocument);
 }
 
@@ -85,17 +85,17 @@ void DocManager::RemoveFromXPCDocumentCa
 
     if (!HasXPCDocuments()) {
       MaybeShutdownAccService(nsAccessibilityService::eXPCOM);
     }
   }
 }
 
 void DocManager::NotifyOfDocumentShutdown(DocAccessible* aDocument,
-                                          nsIDocument* aDOMDocument) {
+                                          Document* aDOMDocument) {
   // We need to remove listeners in both cases, when document is being shutdown
   // or when accessibility service is being shut down as well.
   RemoveListeners(aDOMDocument);
 
   // Document will already be removed when accessibility service is shutting
   // down so we do not need to remove it twice.
   if (nsAccessibilityService::IsShutdown()) {
     return;
@@ -213,17 +213,17 @@ DocManager::OnStateChange(nsIWebProgress
 
   nsCOMPtr<mozIDOMWindowProxy> DOMWindow;
   aWebProgress->GetDOMWindow(getter_AddRefs(DOMWindow));
   NS_ENSURE_STATE(DOMWindow);
 
   nsPIDOMWindowOuter* piWindow = nsPIDOMWindowOuter::From(DOMWindow);
   MOZ_ASSERT(piWindow);
 
-  nsCOMPtr<nsIDocument> document = piWindow->GetDoc();
+  nsCOMPtr<Document> document = piWindow->GetDoc();
   NS_ENSURE_STATE(document);
 
   // Document was loaded.
   if (aStateFlags & STATE_STOP) {
 #ifdef A11Y_LOG
     if (logging::IsEnabled(logging::eDocLoad))
       logging::DocLoad("document loaded", aWebProgress, aRequest, aStateFlags);
 #endif
@@ -311,17 +311,17 @@ DocManager::OnSecurityChange(nsIWebProgr
 ////////////////////////////////////////////////////////////////////////////////
 // nsIDOMEventListener
 
 NS_IMETHODIMP
 DocManager::HandleEvent(Event* aEvent) {
   nsAutoString type;
   aEvent->GetType(type);
 
-  nsCOMPtr<nsIDocument> document = do_QueryInterface(aEvent->GetTarget());
+  nsCOMPtr<Document> document = do_QueryInterface(aEvent->GetTarget());
   NS_ASSERTION(document, "pagehide or DOMContentLoaded for non document!");
   if (!document) return NS_OK;
 
   if (type.EqualsLiteral("pagehide")) {
     // 'pagehide' event is registered on every DOM document we create an
     // accessible for, process the event for the target. This document
     // accessible and all its sub document accessible are shutdown as result of
     // processing.
@@ -356,30 +356,30 @@ DocManager::HandleEvent(Event* aEvent) {
   }
 
   return NS_OK;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // DocManager private
 
-void DocManager::HandleDOMDocumentLoad(nsIDocument* aDocument,
+void DocManager::HandleDOMDocumentLoad(Document* aDocument,
                                        uint32_t aLoadEventType) {
   // Document accessible can be created before we were notified the DOM document
   // was loaded completely. However if it's not created yet then create it.
   DocAccessible* docAcc = GetExistingDocAccessible(aDocument);
   if (!docAcc) {
     docAcc = CreateDocOrRootAccessible(aDocument);
     if (!docAcc) return;
   }
 
   docAcc->NotifyOfLoad(aLoadEventType);
 }
 
-void DocManager::AddListeners(nsIDocument* aDocument,
+void DocManager::AddListeners(Document* aDocument,
                               bool aAddDOMContentLoadedListener) {
   nsPIDOMWindowOuter* window = aDocument->GetWindow();
   EventTarget* target = window->GetChromeEventHandler();
   EventListenerManager* elm = target->GetOrCreateListenerManager();
   elm->AddEventListenerByType(this, NS_LITERAL_STRING("pagehide"),
                               TrustedEventsAtCapture());
 
 #ifdef A11Y_LOG
@@ -392,32 +392,32 @@ void DocManager::AddListeners(nsIDocumen
                                 TrustedEventsAtCapture());
 #ifdef A11Y_LOG
     if (logging::IsEnabled(logging::eDocCreate))
       logging::Text("added 'DOMContentLoaded' listener");
 #endif
   }
 }
 
-void DocManager::RemoveListeners(nsIDocument* aDocument) {
+void DocManager::RemoveListeners(Document* aDocument) {
   nsPIDOMWindowOuter* window = aDocument->GetWindow();
   if (!window) return;
 
   EventTarget* target = window->GetChromeEventHandler();
   if (!target) return;
 
   EventListenerManager* elm = target->GetOrCreateListenerManager();
   elm->RemoveEventListenerByType(this, NS_LITERAL_STRING("pagehide"),
                                  TrustedEventsAtCapture());
 
   elm->RemoveEventListenerByType(this, NS_LITERAL_STRING("DOMContentLoaded"),
                                  TrustedEventsAtCapture());
 }
 
-DocAccessible* DocManager::CreateDocOrRootAccessible(nsIDocument* aDocument) {
+DocAccessible* DocManager::CreateDocOrRootAccessible(Document* aDocument) {
   // Ignore hidden documents, resource documents, static clone
   // (printing) documents and documents without a docshell.
   if (!aDocument->IsVisibleConsideringAncestors() ||
       aDocument->IsResourceDoc() || aDocument->IsStaticDocument() ||
       !aDocument->IsActive()) {
     return nullptr;
   }
 

--- a/accessible/base/DocManager.h
+++ b/accessible/base/DocManager.h
@@ -1,17 +1,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_a11_DocManager_h_
 #define mozilla_a11_DocManager_h_
 
 #include "mozilla/ClearOnShutdown.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIDOMEventListener.h"
 #include "nsRefPtrHashtable.h"
 #include "nsIWebProgressListener.h"
 #include "nsWeakReference.h"
 #include "nsIPresShell.h"
 #include "mozilla/StaticPtr.h"
 
 namespace mozilla {
@@ -31,17 +31,17 @@ class DocManager : public nsIWebProgress
  public:
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_DECL_NSIWEBPROGRESSLISTENER
   NS_DECL_NSIDOMEVENTLISTENER
 
   /**
    * Return document accessible for the given DOM node.
    */
-  DocAccessible* GetDocAccessible(nsIDocument* aDocument);
+  DocAccessible* GetDocAccessible(dom::Document* aDocument);
 
   /**
    * Return document accessible for the given presshell.
    */
   DocAccessible* GetDocAccessible(const nsIPresShell* aPresShell) {
     if (!aPresShell) return nullptr;
 
     DocAccessible* doc = aPresShell->GetDocAccessible();
@@ -55,17 +55,17 @@ class DocManager : public nsIWebProgress
    * unique id.
    */
   Accessible* FindAccessibleInCache(nsINode* aNode) const;
 
   /**
    * Called by document accessible when it gets shutdown.
    */
   void NotifyOfDocumentShutdown(DocAccessible* aDocument,
-                                nsIDocument* aDOMDocument);
+                                dom::Document* aDOMDocument);
 
   void RemoveFromXPCDocumentCache(DocAccessible* aDocument);
 
   /**
    * Return XPCOM accessible document.
    */
   xpcAccessibleDocument* GetXPCDocument(DocAccessible* aDocument);
   xpcAccessibleDocument* GetCachedXPCDocument(DocAccessible* aDocument) const {
@@ -137,35 +137,35 @@ class DocManager : public nsIWebProgress
   /**
    * Create an accessible document if it was't created and fire accessibility
    * events if needed.
    *
    * @param  aDocument       [in] loaded DOM document
    * @param  aLoadEventType  [in] specifies the event type to fire load event,
    *                           if 0 then no event is fired
    */
-  void HandleDOMDocumentLoad(nsIDocument* aDocument, uint32_t aLoadEventType);
+  void HandleDOMDocumentLoad(dom::Document* aDocument, uint32_t aLoadEventType);
 
   /**
    * Add/remove 'pagehide' and 'DOMContentLoaded' event listeners.
    */
-  void AddListeners(nsIDocument* aDocument, bool aAddPageShowListener);
-  void RemoveListeners(nsIDocument* aDocument);
+  void AddListeners(dom::Document* aDocument, bool aAddPageShowListener);
+  void RemoveListeners(dom::Document* aDocument);
 
   /**
    * Create document or root accessible.
    */
-  DocAccessible* CreateDocOrRootAccessible(nsIDocument* aDocument);
+  DocAccessible* CreateDocOrRootAccessible(dom::Document* aDocument);
 
   /**
    * Clear the cache and shutdown the document accessibles.
    */
   void ClearDocCache();
 
-  typedef nsRefPtrHashtable<nsPtrHashKey<const nsIDocument>, DocAccessible>
+  typedef nsRefPtrHashtable<nsPtrHashKey<const dom::Document>, DocAccessible>
       DocAccessibleHashtable;
   DocAccessibleHashtable mDocAccessibleCache;
 
   typedef nsRefPtrHashtable<nsPtrHashKey<const DocAccessible>,
                             xpcAccessibleDocument>
       XPCDocumentHashtable;
   XPCDocumentHashtable mXPCDocumentCache;
   static nsRefPtrHashtable<nsPtrHashKey<const DocAccessibleParent>,
@@ -177,17 +177,17 @@ class DocManager : public nsIWebProgress
   static StaticAutoPtr<nsTArray<DocAccessibleParent*>> sRemoteDocuments;
 };
 
 /**
  * Return the existing document accessible for the document if any.
  * Note this returns the doc accessible for the primary pres shell if there is
  * more than one.
  */
-inline DocAccessible* GetExistingDocAccessible(const nsIDocument* aDocument) {
+inline DocAccessible* GetExistingDocAccessible(const dom::Document* aDocument) {
   nsIPresShell* ps = aDocument->GetShell();
   return ps ? ps->GetDocAccessible() : nullptr;
 }
 
 }  // namespace a11y
 }  // namespace mozilla
 
 #endif  // mozilla_a11_DocManager_h_

--- a/accessible/base/FocusManager.cpp
+++ b/accessible/base/FocusManager.cpp
@@ -129,17 +129,17 @@ void FocusManager::NotifyOfDOMBlur(nsISu
 #endif
 
   mActiveItem = nullptr;
 
   // If DOM document stays focused then fire accessible focus event to process
   // the case when no element within this DOM document will be focused.
   nsCOMPtr<nsINode> targetNode(do_QueryInterface(aTarget));
   if (targetNode && targetNode->OwnerDoc() == FocusedDOMDocument()) {
-    nsIDocument* DOMDoc = targetNode->OwnerDoc();
+    dom::Document* DOMDoc = targetNode->OwnerDoc();
     DocAccessible* document = GetAccService()->GetDocAccessible(DOMDoc);
     if (document) {
       // Clear selection listener for previously focused element.
       if (targetNode->IsElement())
         SelectionMgr()->ClearControlSelectionListener();
 
       document->HandleNotification<FocusManager, nsINode>(
           this, &FocusManager::ProcessDOMFocus, DOMDoc);
@@ -371,15 +371,15 @@ nsINode* FocusManager::FocusedDOMNode() 
     return focusedElm;
   }
 
   // Otherwise the focus can be on DOM document.
   nsPIDOMWindowOuter* focusedWnd = DOMFocusManager->GetFocusedWindow();
   return focusedWnd ? focusedWnd->GetExtantDoc() : nullptr;
 }
 
-nsIDocument* FocusManager::FocusedDOMDocument() const {
+dom::Document* FocusManager::FocusedDOMDocument() const {
   nsINode* focusedNode = FocusedDOMNode();
   return focusedNode ? focusedNode->OwnerDoc() : nullptr;
 }
 
 }  // namespace a11y
 }  // namespace mozilla

--- a/accessible/base/FocusManager.h
+++ b/accessible/base/FocusManager.h
@@ -3,20 +3,23 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_a11y_FocusManager_h_
 #define mozilla_a11y_FocusManager_h_
 
 #include "mozilla/RefPtr.h"
 
 class nsINode;
-class nsIDocument;
 class nsISupports;
 
 namespace mozilla {
+namespace dom {
+class Document;
+}
+
 namespace a11y {
 
 class AccEvent;
 class Accessible;
 class DocAccessible;
 
 /**
  * Manage the accessible focus. Used to fire and process accessible events.
@@ -112,17 +115,17 @@ class FocusManager {
 
  private:
   FocusManager(const FocusManager&);
   FocusManager& operator=(const FocusManager&);
 
   /**
    * Return DOM document having DOM focus.
    */
-  nsIDocument* FocusedDOMDocument() const;
+  dom::Document* FocusedDOMDocument() const;
 
  private:
   RefPtr<Accessible> mActiveItem;
   RefPtr<Accessible> mActiveARIAMenubar;
 };
 
 }  // namespace a11y
 }  // namespace mozilla

--- a/accessible/base/Logging.cpp
+++ b/accessible/base/Logging.cpp
@@ -77,21 +77,21 @@ static void EnableLogging(const char* aM
       }
     }
     token += tokenLen;
 
     if (*token == ',') token++;  // skip ',' char
   }
 }
 
-static void LogDocURI(nsIDocument* aDocumentNode) {
+static void LogDocURI(dom::Document* aDocumentNode) {
   printf("uri: %s", aDocumentNode->GetDocumentURI()->GetSpecOrDefault().get());
 }
 
-static void LogDocShellState(nsIDocument* aDocumentNode) {
+static void LogDocShellState(dom::Document* aDocumentNode) {
   printf("docshell busy: ");
 
   nsAutoCString docShellBusy;
   nsCOMPtr<nsIDocShell> docShell = aDocumentNode->GetDocShell();
   nsIDocShell::BusyFlags busyFlags = nsIDocShell::BUSY_FLAGS_NONE;
   docShell->GetBusyFlags(&busyFlags);
   if (busyFlags == nsIDocShell::BUSY_FLAGS_NONE) {
     printf("'none'");
@@ -102,52 +102,52 @@ static void LogDocShellState(nsIDocument
   if (busyFlags & nsIDocShell::BUSY_FLAGS_BEFORE_PAGE_LOAD) {
     printf(", 'before page load'");
   }
   if (busyFlags & nsIDocShell::BUSY_FLAGS_PAGE_LOADING) {
     printf(", 'page loading'");
   }
 }
 
-static void LogDocType(nsIDocument* aDocumentNode) {
+static void LogDocType(dom::Document* aDocumentNode) {
   if (aDocumentNode->IsActive()) {
     bool isContent = nsCoreUtils::IsContentDocument(aDocumentNode);
     printf("%s document", (isContent ? "content" : "chrome"));
   } else {
     printf("document type: [failed]");
   }
 }
 
-static void LogDocShellTree(nsIDocument* aDocumentNode) {
+static void LogDocShellTree(dom::Document* aDocumentNode) {
   if (aDocumentNode->IsActive()) {
     nsCOMPtr<nsIDocShellTreeItem> treeItem(aDocumentNode->GetDocShell());
     nsCOMPtr<nsIDocShellTreeItem> parentTreeItem;
     treeItem->GetParent(getter_AddRefs(parentTreeItem));
     nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
     treeItem->GetRootTreeItem(getter_AddRefs(rootTreeItem));
     printf("docshell hierarchy, parent: %p, root: %p, is tab document: %s;",
            static_cast<void*>(parentTreeItem), static_cast<void*>(rootTreeItem),
            (nsCoreUtils::IsTabDocument(aDocumentNode) ? "yes" : "no"));
   }
 }
 
-static void LogDocState(nsIDocument* aDocumentNode) {
+static void LogDocState(dom::Document* aDocumentNode) {
   const char* docState = nullptr;
-  nsIDocument::ReadyState docStateFlag = aDocumentNode->GetReadyStateEnum();
+  dom::Document::ReadyState docStateFlag = aDocumentNode->GetReadyStateEnum();
   switch (docStateFlag) {
-    case nsIDocument::READYSTATE_UNINITIALIZED:
+    case dom::Document::READYSTATE_UNINITIALIZED:
       docState = "uninitialized";
       break;
-    case nsIDocument::READYSTATE_LOADING:
+    case dom::Document::READYSTATE_LOADING:
       docState = "loading";
       break;
-    case nsIDocument::READYSTATE_INTERACTIVE:
+    case dom::Document::READYSTATE_INTERACTIVE:
       docState = "interactive";
       break;
-    case nsIDocument::READYSTATE_COMPLETE:
+    case dom::Document::READYSTATE_COMPLETE:
       docState = "complete";
       break;
   }
 
   printf("doc state: %s", docState);
   printf(", %sinitial", aDocumentNode->IsInitialDocument() ? "" : "not ");
   printf(", %sshowing", aDocumentNode->IsShowing() ? "" : "not ");
   printf(", %svisible", aDocumentNode->IsVisible() ? "" : "not ");
@@ -158,46 +158,46 @@ static void LogDocState(nsIDocument* aDo
 
   dom::Element* rootEl = aDocumentNode->GetBodyElement();
   if (!rootEl) {
     rootEl = aDocumentNode->GetRootElement();
   }
   printf(", has %srole content", rootEl ? "" : "no ");
 }
 
-static void LogPresShell(nsIDocument* aDocumentNode) {
+static void LogPresShell(dom::Document* aDocumentNode) {
   nsIPresShell* ps = aDocumentNode->GetShell();
   printf("presshell: %p", static_cast<void*>(ps));
 
   nsIScrollableFrame* sf = nullptr;
   if (ps) {
     printf(", is %s destroying", (ps->IsDestroying() ? "" : "not"));
     sf = ps->GetRootScrollFrameAsScrollable();
   }
   printf(", root scroll frame: %p", static_cast<void*>(sf));
 }
 
-static void LogDocLoadGroup(nsIDocument* aDocumentNode) {
+static void LogDocLoadGroup(dom::Document* aDocumentNode) {
   nsCOMPtr<nsILoadGroup> loadGroup = aDocumentNode->GetDocumentLoadGroup();
   printf("load group: %p", static_cast<void*>(loadGroup));
 }
 
-static void LogDocParent(nsIDocument* aDocumentNode) {
-  nsIDocument* parentDoc = aDocumentNode->GetParentDocument();
+static void LogDocParent(dom::Document* aDocumentNode) {
+  dom::Document* parentDoc = aDocumentNode->GetParentDocument();
   printf("parent DOM document: %p", static_cast<void*>(parentDoc));
   if (parentDoc) {
     printf(", parent acc document: %p",
            static_cast<void*>(GetExistingDocAccessible(parentDoc)));
     printf("\n    parent ");
     LogDocURI(parentDoc);
     printf("\n");
   }
 }
 
-static void LogDocInfo(nsIDocument* aDocumentNode, DocAccessible* aDocument) {
+static void LogDocInfo(dom::Document* aDocumentNode, DocAccessible* aDocument) {
   printf("    DOM document: %p, acc document: %p\n    ",
          static_cast<void*>(aDocumentNode), static_cast<void*>(aDocument));
 
   // log document info
   if (aDocumentNode) {
     LogDocURI(aDocumentNode);
     printf("\n    ");
     LogDocShellState(aDocumentNode);
@@ -365,17 +365,17 @@ void logging::DocLoad(const char* aMsg, 
   nsCOMPtr<mozIDOMWindowProxy> DOMWindow;
   aWebProgress->GetDOMWindow(getter_AddRefs(DOMWindow));
   nsPIDOMWindowOuter* window = nsPIDOMWindowOuter::From(DOMWindow);
   if (!window) {
     MsgEnd();
     return;
   }
 
-  nsCOMPtr<nsIDocument> documentNode = window->GetDoc();
+  nsCOMPtr<dom::Document> documentNode = window->GetDoc();
   if (!documentNode) {
     MsgEnd();
     return;
   }
 
   DocAccessible* document = GetExistingDocAccessible(documentNode);
 
   LogDocInfo(documentNode, document);
@@ -389,17 +389,17 @@ void logging::DocLoad(const char* aMsg, 
   printf("    state flags: %x", aStateFlags);
   bool isDocLoading;
   aWebProgress->GetIsLoadingDocument(&isDocLoading);
   printf(", document is %sloading\n", (isDocLoading ? "" : "not "));
 
   MsgEnd();
 }
 
-void logging::DocLoad(const char* aMsg, nsIDocument* aDocumentNode) {
+void logging::DocLoad(const char* aMsg, dom::Document* aDocumentNode) {
   MsgBegin(sDocLoadTitle, "%s", aMsg);
 
   DocAccessible* document = GetExistingDocAccessible(aDocumentNode);
   LogDocInfo(aDocumentNode, document);
 
   MsgEnd();
 }
 
@@ -439,27 +439,27 @@ void logging::DocLoadEventHandled(AccEve
   MsgBegin(sDocEventTitle, "handled '%s' event", strEventType.get());
 
   DocAccessible* document = aEvent->GetAccessible()->AsDoc();
   if (document) LogDocInfo(document->DocumentNode(), document);
 
   MsgEnd();
 }
 
-void logging::DocCreate(const char* aMsg, nsIDocument* aDocumentNode,
+void logging::DocCreate(const char* aMsg, dom::Document* aDocumentNode,
                         DocAccessible* aDocument) {
   DocAccessible* document =
       aDocument ? aDocument : GetExistingDocAccessible(aDocumentNode);
 
   MsgBegin(sDocCreateTitle, "%s", aMsg);
   LogDocInfo(aDocumentNode, document);
   MsgEnd();
 }
 
-void logging::DocDestroy(const char* aMsg, nsIDocument* aDocumentNode,
+void logging::DocDestroy(const char* aMsg, dom::Document* aDocumentNode,
                          DocAccessible* aDocument) {
   DocAccessible* document =
       aDocument ? aDocument : GetExistingDocAccessible(aDocumentNode);
 
   MsgBegin(sDocDestroyTitle, "%s", aMsg);
   LogDocInfo(aDocumentNode, document);
   MsgEnd();
 }
@@ -708,17 +708,17 @@ void logging::Text(const char* aText) { 
 
 void logging::Address(const char* aDescr, Accessible* aAcc) {
   if (!aAcc->IsDoc()) {
     printf("    %s accessible: %p, node: %p\n", aDescr,
            static_cast<void*>(aAcc), static_cast<void*>(aAcc->GetNode()));
   }
 
   DocAccessible* doc = aAcc->Document();
-  nsIDocument* docNode = doc->DocumentNode();
+  dom::Document* docNode = doc->DocumentNode();
   printf("    document: %p, node: %p\n", static_cast<void*>(doc),
          static_cast<void*>(docNode));
 
   printf("    ");
   LogDocURI(docNode);
   printf("\n");
 }
 

--- a/accessible/base/Logging.h
+++ b/accessible/base/Logging.h
@@ -6,25 +6,25 @@
 
 #ifndef mozilla_a11y_logs_h__
 #define mozilla_a11y_logs_h__
 
 #include "nscore.h"
 #include "nsStringFwd.h"
 #include "mozilla/Attributes.h"
 
-class nsIDocument;
 class nsINode;
 class nsIRequest;
 class nsISupports;
 class nsIWebProgress;
 
 namespace mozilla {
 
 namespace dom {
+class Document;
 class Selection;
 }  // namespace dom
 
 namespace a11y {
 
 class AccEvent;
 class Accessible;
 class DocAccessible;
@@ -69,39 +69,39 @@ bool IsEnabledAll(uint32_t aModules);
  */
 bool IsEnabled(const nsAString& aModules);
 
 /**
  * Log the document loading progress.
  */
 void DocLoad(const char* aMsg, nsIWebProgress* aWebProgress,
              nsIRequest* aRequest, uint32_t aStateFlags);
-void DocLoad(const char* aMsg, nsIDocument* aDocumentNode);
+void DocLoad(const char* aMsg, dom::Document* aDocumentNode);
 void DocCompleteLoad(DocAccessible* aDocument, bool aIsLoadEventTarget);
 
 /**
  * Log that document load event was fired.
  */
 void DocLoadEventFired(AccEvent* aEvent);
 
 /**
  * Log that document laod event was handled.
  */
 void DocLoadEventHandled(AccEvent* aEvent);
 
 /**
  * Log the document was created.
  */
-void DocCreate(const char* aMsg, nsIDocument* aDocumentNode,
+void DocCreate(const char* aMsg, dom::Document* aDocumentNode,
                DocAccessible* aDocument = nullptr);
 
 /**
  * Log the document was destroyed.
  */
-void DocDestroy(const char* aMsg, nsIDocument* aDocumentNode,
+void DocDestroy(const char* aMsg, dom::Document* aDocumentNode,
                 DocAccessible* aDocument = nullptr);
 
 /**
  * Log the outer document was destroyed.
  */
 void OuterDocDestroy(OuterDocAccessible* OuterDoc);
 
 /**

--- a/accessible/base/SelectionManager.cpp
+++ b/accessible/base/SelectionManager.cpp
@@ -10,17 +10,17 @@
 #include "HyperTextAccessible-inl.h"
 #include "nsAccessibilityService.h"
 #include "nsAccUtils.h"
 #include "nsCoreUtils.h"
 #include "nsEventShell.h"
 #include "nsFrameSelection.h"
 
 #include "nsIAccessibleTypes.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIPresShell.h"
 #include "mozilla/dom/Selection.h"
 #include "mozilla/dom/Element.h"
 
 using namespace mozilla;
 using namespace mozilla::a11y;
 using mozilla::dom::Selection;
 
@@ -133,17 +133,17 @@ void SelectionManager::ProcessTextSelCha
   if (mCaretOffset != -1) {
     RefPtr<AccCaretMoveEvent> caretMoveEvent =
         new AccCaretMoveEvent(caretCntr, mCaretOffset, aEvent->FromUserInput());
     nsEventShell::FireEvent(caretMoveEvent);
   }
 }
 
 NS_IMETHODIMP
-SelectionManager::NotifySelectionChanged(nsIDocument* aDocument,
+SelectionManager::NotifySelectionChanged(dom::Document* aDocument,
                                          Selection* aSelection,
                                          int16_t aReason) {
   if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {
     return NS_ERROR_INVALID_ARG;
   }
 
   DocAccessible* document = GetAccService()->GetDocAccessible(aDocument);
 

--- a/accessible/base/nsAccUtils.cpp
+++ b/accessible/base/nsAccUtils.cpp
@@ -444,17 +444,17 @@ bool nsAccUtils::IsARIALive(const Access
   // Get computed aria-live property based on the closest container with the
   // attribute. Inner nodes override outer nodes within the same
   // document, but nodes in outer documents override nodes in inner documents.
   // This should be the same as the container-live attribute, but we don't need
   // the other container-* attributes, so we can't use the same function.
   nsAutoString live;
   nsIContent* startContent = aAccessible->GetContent();
   while (startContent) {
-    nsIDocument* doc = startContent->GetComposedDoc();
+    dom::Document* doc = startContent->GetComposedDoc();
     if (!doc) {
       break;
     }
 
     dom::Element* aTopEl = doc->GetRootElement();
     nsIContent* ancestor = startContent;
     while (ancestor) {
       nsAutoString docLive;
@@ -490,17 +490,17 @@ bool nsAccUtils::IsARIALive(const Access
     }
 
     nsCOMPtr<nsIDocShellTreeItem> sameTypeParent;
     docShellTreeItem->GetSameTypeParent(getter_AddRefs(sameTypeParent));
     if (!sameTypeParent || sameTypeParent == docShellTreeItem) {
       break;
     }
 
-    nsIDocument* parentDoc = doc->GetParentDocument();
+    dom::Document* parentDoc = doc->GetParentDocument();
     if (!parentDoc) {
       break;
     }
 
     startContent = parentDoc->FindContentForSubDocument(doc);
   }
 
   return !live.IsEmpty() && !live.EqualsLiteral("off");

--- a/accessible/base/nsAccessibilityService.cpp
+++ b/accessible/base/nsAccessibilityService.cpp
@@ -277,17 +277,17 @@ nsAccessibilityService::ListenersChanged
       continue;
     }
 
     uint32_t changeCount;
     change->GetCountOfEventListenerChangesAffectingAccessibility(&changeCount);
     NS_ENSURE_SUCCESS(rv, rv);
 
     for (uint32_t i = 0; i < changeCount; i++) {
-      nsIDocument* ownerDoc = node->OwnerDoc();
+      Document* ownerDoc = node->OwnerDoc();
       DocAccessible* document = GetExistingDocAccessible(ownerDoc);
 
       // Create an accessible for a inaccessible element having click event
       // handler.
       if (document && !document->HasAccessible(node) &&
           nsCoreUtils::HasClickListener(node)) {
         document->ContentInserted(node, node->GetNextSibling());
         break;
@@ -313,32 +313,32 @@ nsAccessibilityService::Observe(nsISuppo
   if (!nsCRT::strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
     Shutdown();
   }
 
   return NS_OK;
 }
 
 void nsAccessibilityService::NotifyOfAnchorJumpTo(nsIContent* aTargetNode) {
-  nsIDocument* documentNode = aTargetNode->GetUncomposedDoc();
+  Document* documentNode = aTargetNode->GetUncomposedDoc();
   if (documentNode) {
     DocAccessible* document = GetDocAccessible(documentNode);
     if (document) document->SetAnchorJump(aTargetNode);
   }
 }
 
 void nsAccessibilityService::FireAccessibleEvent(uint32_t aEvent,
                                                  Accessible* aTarget) {
   nsEventShell::FireEvent(aEvent, aTarget);
 }
 
 Accessible* nsAccessibilityService::GetRootDocumentAccessible(
     nsIPresShell* aPresShell, bool aCanCreate) {
   nsIPresShell* ps = aPresShell;
-  nsIDocument* documentNode = aPresShell->GetDocument();
+  Document* documentNode = aPresShell->GetDocument();
   if (documentNode) {
     nsCOMPtr<nsIDocShellTreeItem> treeItem(documentNode->GetDocShell());
     if (treeItem) {
       nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
       treeItem->GetRootTreeItem(getter_AddRefs(rootTreeItem));
       if (treeItem != rootTreeItem) {
         nsCOMPtr<nsIDocShell> docShell(do_QueryInterface(rootTreeItem));
         ps = docShell->GetPresShell();

--- a/accessible/base/nsCoreUtils.cpp
+++ b/accessible/base/nsCoreUtils.cpp
@@ -4,17 +4,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsCoreUtils.h"
 
 #include "nsIAccessibleTypes.h"
 
 #include "nsIBaseWindow.h"
 #include "nsIDocShellTreeOwner.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsRange.h"
 #include "nsIBoxObject.h"
 #include "nsXULElement.h"
 #include "mozilla/dom/BoxObject.h"
 #include "nsIDocShell.h"
 #include "nsIObserverService.h"
 #include "nsIPresShell.h"
 #include "nsPresContext.h"
@@ -65,17 +65,17 @@ bool nsCoreUtils::HasClickListener(nsICo
 
 void nsCoreUtils::DispatchClickEvent(nsITreeBoxObject *aTreeBoxObj,
                                      int32_t aRowIndex, nsTreeColumn *aColumn,
                                      const nsAString &aPseudoElt) {
   RefPtr<dom::Element> tcElm;
   aTreeBoxObj->GetTreeBody(getter_AddRefs(tcElm));
   if (!tcElm) return;
 
-  nsIDocument *document = tcElm->GetUncomposedDoc();
+  Document *document = tcElm->GetUncomposedDoc();
   if (!document) return;
 
   nsCOMPtr<nsIPresShell> presShell = document->GetShell();
   if (!presShell) return;
 
   // Ensure row is visible.
   aTreeBoxObj->EnsureRowIsVisible(aRowIndex);
 
@@ -335,50 +335,50 @@ nsIntPoint nsCoreUtils::GetScreenCoordsF
 
 already_AddRefed<nsIDocShell> nsCoreUtils::GetDocShellFor(nsINode *aNode) {
   if (!aNode) return nullptr;
 
   nsCOMPtr<nsIDocShell> docShell = aNode->OwnerDoc()->GetDocShell();
   return docShell.forget();
 }
 
-bool nsCoreUtils::IsRootDocument(nsIDocument *aDocument) {
+bool nsCoreUtils::IsRootDocument(Document *aDocument) {
   nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = aDocument->GetDocShell();
   NS_ASSERTION(docShellTreeItem, "No document shell for document!");
 
   nsCOMPtr<nsIDocShellTreeItem> parentTreeItem;
   docShellTreeItem->GetParent(getter_AddRefs(parentTreeItem));
 
   return !parentTreeItem;
 }
 
-bool nsCoreUtils::IsContentDocument(nsIDocument *aDocument) {
+bool nsCoreUtils::IsContentDocument(Document *aDocument) {
   nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = aDocument->GetDocShell();
   NS_ASSERTION(docShellTreeItem, "No document shell tree item for document!");
 
   return (docShellTreeItem->ItemType() == nsIDocShellTreeItem::typeContent);
 }
 
-bool nsCoreUtils::IsTabDocument(nsIDocument *aDocumentNode) {
+bool nsCoreUtils::IsTabDocument(Document *aDocumentNode) {
   nsCOMPtr<nsIDocShellTreeItem> treeItem(aDocumentNode->GetDocShell());
 
   nsCOMPtr<nsIDocShellTreeItem> parentTreeItem;
   treeItem->GetParent(getter_AddRefs(parentTreeItem));
 
   // Tab document running in own process doesn't have parent.
   if (XRE_IsContentProcess()) return !parentTreeItem;
 
   // Parent of docshell for tab document running in chrome process is root.
   nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
   treeItem->GetRootTreeItem(getter_AddRefs(rootTreeItem));
 
   return parentTreeItem == rootTreeItem;
 }
 
-bool nsCoreUtils::IsErrorPage(nsIDocument *aDocument) {
+bool nsCoreUtils::IsErrorPage(Document *aDocument) {
   nsIURI *uri = aDocument->GetDocumentURI();
   bool isAboutScheme = false;
   uri->SchemeIs("about", &isAboutScheme);
   if (!isAboutScheme) return false;
 
   nsAutoCString path;
   uri->GetPathQueryRef(path);
 

--- a/accessible/base/nsCoreUtils.h
+++ b/accessible/base/nsCoreUtils.h
@@ -5,17 +5,17 @@
 
 #ifndef nsCoreUtils_h_
 #define nsCoreUtils_h_
 
 #include "mozilla/EventForwards.h"
 #include "mozilla/dom/Element.h"
 #include "nsIAccessibleEvent.h"
 #include "nsIContent.h"
-#include "nsIDocument.h"  // for GetShell()
+#include "mozilla/dom/Document.h"  // for GetShell()
 #include "nsIPresShell.h"
 
 #include "nsPoint.h"
 #include "nsTArray.h"
 
 class nsRange;
 class nsTreeColumn;
 class nsIBoxObject;
@@ -24,16 +24,18 @@ class nsIDocShell;
 class nsITreeBoxObject;
 class nsIWidget;
 
 /**
  * Core utils.
  */
 class nsCoreUtils {
  public:
+  typedef mozilla::dom::Document Document;
+
   /**
    * Return true if the given node is a label of a control.
    */
   static bool IsLabelWithControl(nsIContent *aContent);
 
   /**
    * Return true if the given node has registered click, mousedown or mouseup
    * event listeners.
@@ -180,32 +182,32 @@ class nsCoreUtils {
   /**
    * Return document shell for the given DOM node.
    */
   static already_AddRefed<nsIDocShell> GetDocShellFor(nsINode *aNode);
 
   /**
    * Return true if the given document is root document.
    */
-  static bool IsRootDocument(nsIDocument *aDocument);
+  static bool IsRootDocument(Document *aDocument);
 
   /**
    * Return true if the given document is content document (not chrome).
    */
-  static bool IsContentDocument(nsIDocument *aDocument);
+  static bool IsContentDocument(Document *aDocument);
 
   /**
    * Return true if the given document node is for tab document accessible.
    */
-  static bool IsTabDocument(nsIDocument *aDocumentNode);
+  static bool IsTabDocument(Document *aDocumentNode);
 
   /**
    * Return true if the given document is an error page.
    */
-  static bool IsErrorPage(nsIDocument *aDocument);
+  static bool IsErrorPage(Document *aDocument);
 
   /**
    * Return presShell for the document containing the given DOM node.
    */
   static nsIPresShell *GetPresShellFor(nsINode *aNode) {
     return aNode->OwnerDoc()->GetShell();
   }
 

--- a/accessible/generic/Accessible.cpp
+++ b/accessible/generic/Accessible.cpp
@@ -32,17 +32,17 @@
 #include "XULDocument.h"
 
 #include "nsIDOMXULButtonElement.h"
 #include "nsIDOMXULSelectCntrlEl.h"
 #include "nsIDOMXULSelectCntrlItemEl.h"
 #include "nsINodeList.h"
 #include "nsPIDOMWindow.h"
 
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIContent.h"
 #include "nsIForm.h"
 #include "nsIFormControl.h"
 
 #include "nsDeckFrame.h"
 #include "nsLayoutUtils.h"
 #include "nsIPresShell.h"
 #include "nsIStringBundle.h"
@@ -260,17 +260,17 @@ KeyBinding Accessible::AccessKey() const
       return KeyBinding(key, KeyBinding::kAlt);
     case dom::KeyboardEvent_Binding::DOM_VK_META:
       return KeyBinding(key, KeyBinding::kMeta);
     default:
       return KeyBinding();
   }
 
   // Determine the access modifier used in this context.
-  nsIDocument* document = mContent->GetUncomposedDoc();
+  dom::Document* document = mContent->GetUncomposedDoc();
   if (!document) return KeyBinding();
 
   nsCOMPtr<nsIDocShellTreeItem> treeItem(document->GetDocShell());
   if (!treeItem) return KeyBinding();
 
   nsresult rv = NS_ERROR_FAILURE;
   int32_t modifierMask = 0;
   switch (treeItem->ItemType()) {
@@ -1020,31 +1020,31 @@ already_AddRefed<nsIPersistentProperties
   // Get container-foo computed live region properties based on the closest
   // container with the live region attribute. Inner nodes override outer nodes
   // within the same document. The inner nodes can be used to override live
   // region behavior on more general outer nodes. However, nodes in outer
   // documents override nodes in inner documents: outer doc author may want to
   // override properties on a widget they used in an iframe.
   nsIContent* startContent = mContent;
   while (startContent) {
-    nsIDocument* doc = startContent->GetComposedDoc();
+    dom::Document* doc = startContent->GetComposedDoc();
     if (!doc) break;
 
     nsAccUtils::SetLiveContainerAttributes(attributes, startContent,
                                            doc->GetRootElement());
 
     // Allow ARIA live region markup from outer documents to override
     nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = doc->GetDocShell();
     if (!docShellTreeItem) break;
 
     nsCOMPtr<nsIDocShellTreeItem> sameTypeParent;
     docShellTreeItem->GetSameTypeParent(getter_AddRefs(sameTypeParent));
     if (!sameTypeParent || sameTypeParent == docShellTreeItem) break;
 
-    nsIDocument* parentDoc = doc->GetParentDocument();
+    dom::Document* parentDoc = doc->GetParentDocument();
     if (!parentDoc) break;
 
     startContent = parentDoc->FindContentForSubDocument(doc);
   }
 
   if (!mContent->IsElement()) return attributes.forget();
 
   nsAutoString id;
@@ -1682,17 +1682,17 @@ Relation Accessible::RelationByType(Rela
           if (form) {
             nsCOMPtr<nsIContent> formContent =
                 do_QueryInterface(form->GetDefaultSubmitElement());
             return Relation(mDoc, formContent);
           }
         }
       } else {
         // In XUL, use first <button default="true" .../> in the document
-        nsIDocument* doc = mContent->OwnerDoc();
+        dom::Document* doc = mContent->OwnerDoc();
         nsIContent* buttonEl = nullptr;
         if (doc->IsXULDocument()) {
           dom::XULDocument* xulDoc = doc->AsXULDocument();
           nsCOMPtr<nsIHTMLCollection> possibleDefaultButtons =
               xulDoc->GetElementsByAttribute(NS_LITERAL_STRING("default"),
                                              NS_LITERAL_STRING("true"));
           if (possibleDefaultButtons) {
             uint32_t length = possibleDefaultButtons->Length();
@@ -2388,17 +2388,17 @@ Accessible* Accessible::CurrentItem() co
   // Check for aria-activedescendant, which changes which element has focus.
   // For activedescendant, the ARIA spec does not require that the user agent
   // checks whether pointed node is actually a DOM descendant of the element
   // with the aria-activedescendant attribute.
   nsAutoString id;
   if (HasOwnContent() && mContent->IsElement() &&
       mContent->AsElement()->GetAttr(kNameSpaceID_None,
                                      nsGkAtoms::aria_activedescendant, id)) {
-    nsIDocument* DOMDoc = mContent->OwnerDoc();
+    dom::Document* DOMDoc = mContent->OwnerDoc();
     dom::Element* activeDescendantElm = DOMDoc->GetElementById(id);
     if (activeDescendantElm) {
       DocAccessible* document = Document();
       if (document) return document->GetAccessible(activeDescendantElm);
     }
   }
   return nullptr;
 }

--- a/accessible/generic/ApplicationAccessible.cpp
+++ b/accessible/generic/ApplicationAccessible.cpp
@@ -120,19 +120,17 @@ void ApplicationAccessible::Init() {
 
   if (!windowsById) {
     return;
   }
 
   for (auto iter = windowsById->Iter(); !iter.Done(); iter.Next()) {
     nsGlobalWindowOuter* window = iter.Data();
     if (window->GetDocShell() && window->IsRootOuterWindow()) {
-      nsCOMPtr<nsIDocument> docNode = window->GetExtantDoc();
-
-      if (docNode) {
+      if (RefPtr<dom::Document> docNode = window->GetExtantDoc()) {
         GetAccService()->GetDocAccessible(docNode);  // ensure creation
       }
     }
   }
 }
 
 Accessible* ApplicationAccessible::GetSiblingAtOffset(int32_t aOffset,
                                                       nsresult* aError) const {

--- a/accessible/generic/DocAccessible-inl.h
+++ b/accessible/generic/DocAccessible-inl.h
@@ -8,17 +8,17 @@
 #define mozilla_a11y_DocAccessible_inl_h_
 
 #include "DocAccessible.h"
 #include "nsAccessibilityService.h"
 #include "nsAccessiblePivot.h"
 #include "NotificationController.h"
 #include "States.h"
 #include "nsIScrollableFrame.h"
-#include "nsIDocumentInlines.h"
+#include "mozilla/dom/DocumentInlines.h"
 
 #ifdef A11Y_LOG
 #include "Logging.h"
 #endif
 
 namespace mozilla {
 namespace a11y {
 

--- a/accessible/generic/DocAccessible.cpp
+++ b/accessible/generic/DocAccessible.cpp
@@ -18,17 +18,17 @@
 #include "RootAccessible.h"
 #include "TreeWalker.h"
 #include "xpcAccessibleDocument.h"
 
 #include "nsContentUtils.h"
 #include "nsIMutableArray.h"
 #include "nsICommandManager.h"
 #include "nsIDocShell.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsPIDOMWindow.h"
 #include "nsIEditingSession.h"
 #include "nsIFrame.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsImageFrame.h"
 #include "nsIPersistentProperties2.h"
 #include "nsIPresShell.h"
 #include "nsIServiceManager.h"
@@ -65,17 +65,17 @@ static nsStaticAtom* const kRelationAttr
                                                nsGkAtoms::_for,
                                                nsGkAtoms::control};
 
 static const uint32_t kRelationAttrsLen = ArrayLength(kRelationAttrs);
 
 ////////////////////////////////////////////////////////////////////////////////
 // Constructor/desctructor
 
-DocAccessible::DocAccessible(nsIDocument* aDocument, nsIPresShell* aPresShell)
+DocAccessible::DocAccessible(dom::Document* aDocument, nsIPresShell* aPresShell)
     :  // XXX don't pass a document to the Accessible constructor so that we
        // don't set mDoc until our vtable is fully setup.  If we set mDoc before
        // setting up the vtable we will call Accessible::AddRef() but not the
        // overrides of it for subclasses.  It is important to call those
        // overrides to avoid confusing leak checking machinary.
       HyperTextAccessibleWrap(nullptr, nullptr),
       // XXX aaronl should we use an algorithm for the initial cache size?
       mAccessibleCache(kDefaultCacheLength),
@@ -367,17 +367,17 @@ void DocAccessible::Init() {
 #endif
 
   // Initialize notification controller.
   mNotificationController = new NotificationController(this, mPresShell);
 
   // Mark the document accessible as loaded if its DOM document was loaded at
   // this point (this can happen because a11y is started late or DOM document
   // having no container was loaded.
-  if (mDocumentNode->GetReadyStateEnum() == nsIDocument::READYSTATE_COMPLETE)
+  if (mDocumentNode->GetReadyStateEnum() == dom::Document::READYSTATE_COMPLETE)
     mLoadState |= eDOMLoaded;
 
   AddEventListeners();
 }
 
 void DocAccessible::Shutdown() {
   if (!mPresShell)  // already shutdown
     return;
@@ -456,18 +456,18 @@ nsIFrame* DocAccessible::GetFrame() cons
 
   return root;
 }
 
 // DocAccessible protected member
 nsRect DocAccessible::RelativeBounds(nsIFrame** aRelativeFrame) const {
   *aRelativeFrame = GetFrame();
 
-  nsIDocument* document = mDocumentNode;
-  nsIDocument* parentDoc = nullptr;
+  dom::Document* document = mDocumentNode;
+  dom::Document* parentDoc = nullptr;
 
   nsRect bounds;
   while (document) {
     nsIPresShell* presShell = document->GetShell();
     if (!presShell) return nsRect();
 
     nsRect scrollPort;
     nsIScrollableFrame* sf = presShell->GetRootScrollFrameAsScrollable();
@@ -1015,17 +1015,17 @@ void DocAccessible::ARIAActiveDescendant
                                         aAccessible);
     }
 #endif
   }
 }
 
 void DocAccessible::ContentAppended(nsIContent* aFirstNewContent) {}
 
-void DocAccessible::ContentStateChanged(nsIDocument* aDocument,
+void DocAccessible::ContentStateChanged(dom::Document* aDocument,
                                         nsIContent* aContent,
                                         EventStates aStateMask) {
   Accessible* accessible = GetAccessible(aContent);
   if (!accessible) return;
 
   if (aStateMask.HasState(NS_EVENT_STATE_CHECKED)) {
     Accessible* widget = accessible->ContainerWidget();
     if (widget && widget->IsSelect()) {
@@ -1053,17 +1053,17 @@ void DocAccessible::ContentStateChanged(
 
   if (aStateMask.HasState(NS_EVENT_STATE_VISITED)) {
     RefPtr<AccEvent> event =
         new AccStateChangeEvent(accessible, states::TRAVERSED, true);
     FireDelayedEvent(event);
   }
 }
 
-void DocAccessible::DocumentStatesChanged(nsIDocument* aDocument,
+void DocAccessible::DocumentStatesChanged(dom::Document* aDocument,
                                           EventStates aStateMask) {}
 
 void DocAccessible::CharacterDataWillChange(nsIContent* aContent,
                                             const CharacterDataChangeInfo&) {}
 
 void DocAccessible::CharacterDataChanged(nsIContent* aContent,
                                          const CharacterDataChangeInfo&) {}
 

--- a/accessible/generic/DocAccessible.h
+++ b/accessible/generic/DocAccessible.h
@@ -9,31 +9,35 @@
 #include "nsIAccessiblePivot.h"
 
 #include "HyperTextAccessibleWrap.h"
 #include "AccEvent.h"
 
 #include "nsAutoPtr.h"
 #include "nsClassHashtable.h"
 #include "nsDataHashtable.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIDocumentObserver.h"
 #include "nsIObserver.h"
 #include "nsIScrollPositionListener.h"
 #include "nsITimer.h"
 #include "nsIWeakReference.h"
 
 class nsAccessiblePivot;
 
 const uint32_t kDefaultCacheLength = 128;
 
 namespace mozilla {
 
 class TextEditor;
 
+namespace dom {
+class Document;
+}
+
 namespace a11y {
 
 class DocManager;
 class NotificationController;
 class DocAccessibleChild;
 class RelatedAccIterator;
 template <class Class, class... Args>
 class TNotification;
@@ -45,32 +49,35 @@ class DocAccessible : public HyperTextAc
                       public nsSupportsWeakReference,
                       public nsIAccessiblePivotObserver {
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DocAccessible, Accessible)
 
   NS_DECL_NSIOBSERVER
   NS_DECL_NSIACCESSIBLEPIVOTOBSERVER
 
+ protected:
+  typedef mozilla::dom::Document Document;
+
  public:
-  DocAccessible(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  DocAccessible(Document* aDocument, nsIPresShell* aPresShell);
 
   // nsIScrollPositionListener
   virtual void ScrollPositionWillChange(nscoord aX, nscoord aY) override {}
   virtual void ScrollPositionDidChange(nscoord aX, nscoord aY) override;
 
   // nsIDocumentObserver
   NS_DECL_NSIDOCUMENTOBSERVER
 
   // Accessible
   virtual void Init();
   virtual void Shutdown() override;
   virtual nsIFrame* GetFrame() const override;
   virtual nsINode* GetNode() const override { return mDocumentNode; }
-  nsIDocument* DocumentNode() const { return mDocumentNode; }
+  Document* DocumentNode() const { return mDocumentNode; }
 
   virtual mozilla::a11y::ENameValueFlag Name(nsString& aName) const override;
   virtual void Description(nsString& aDescription) override;
   virtual Accessible* FocusedChild() override;
   virtual mozilla::a11y::role NativeRole() const override;
   virtual uint64_t NativeState() const override;
   virtual uint64_t NativeInteractiveState() const override;
   virtual bool NativelyUnavailable() const override;
@@ -128,17 +135,17 @@ class DocAccessible : public HyperTextAc
   nsPresContext* PresContext() const { return mPresShell->GetPresContext(); }
 
   /**
    * Return true if associated DOM document was loaded and isn't unloading.
    */
   bool IsContentLoaded() const {
     // eDOMLoaded flag check is used for error pages as workaround to make this
     // method return correct result since error pages do not receive 'pageshow'
-    // event and as consequence nsIDocument::IsShowing() returns false.
+    // event and as consequence Document::IsShowing() returns false.
     return mDocumentNode && mDocumentNode->IsVisible() &&
            (mDocumentNode->IsShowing() || HasLoadState(eDOMLoaded));
   }
 
   bool IsHidden() const { return mDocumentNode->Hidden(); }
 
   /**
    * Document load states.
@@ -591,17 +598,17 @@ class DocAccessible : public HyperTextAc
 
   /**
    * Cache of accessibles within this document accessible.
    */
   AccessibleHashtable mAccessibleCache;
   nsDataHashtable<nsPtrHashKey<const nsINode>, Accessible*>
       mNodeToAccessibleMap;
 
-  nsIDocument* mDocumentNode;
+  Document* mDocumentNode;
   nsCOMPtr<nsITimer> mScrollWatchTimer;
   uint16_t mScrollPositionChangedTicks;  // Used for tracking scroll events
   TimeStamp mLastScrollingDispatch;
 
   /**
    * Bit mask of document load states (@see LoadState).
    */
   uint32_t mLoadState : 3;

--- a/accessible/generic/HyperTextAccessible.cpp
+++ b/accessible/generic/HyperTextAccessible.cpp
@@ -1233,17 +1233,17 @@ already_AddRefed<TextEditor> HyperTextAc
     return nullptr;
   }
 
   nsCOMPtr<nsIDocShell> docShell = nsCoreUtils::GetDocShellFor(mContent);
   nsCOMPtr<nsIEditingSession> editingSession;
   docShell->GetEditingSession(getter_AddRefs(editingSession));
   if (!editingSession) return nullptr;  // No editing session interface
 
-  nsIDocument* docNode = mDoc->DocumentNode();
+  dom::Document* docNode = mDoc->DocumentNode();
   RefPtr<HTMLEditor> htmlEditor =
       editingSession->GetHTMLEditorForWindow(docNode->GetWindow());
   return htmlEditor.forget();
 }
 
 /**
  * =================== Caret & Selection ======================
  */
@@ -1283,17 +1283,17 @@ nsresult HyperTextAccessible::SetSelecti
   // When selection is done, move the focus to the selection if accessible is
   // not focusable. That happens when selection is set within hypertext
   // accessible.
   if (isFocusable) return NS_OK;
 
   nsFocusManager* DOMFocusManager = nsFocusManager::GetFocusManager();
   if (DOMFocusManager) {
     NS_ENSURE_TRUE(mDoc, NS_ERROR_FAILURE);
-    nsIDocument* docNode = mDoc->DocumentNode();
+    dom::Document* docNode = mDoc->DocumentNode();
     NS_ENSURE_TRUE(docNode, NS_ERROR_FAILURE);
     nsCOMPtr<nsPIDOMWindowOuter> window = docNode->GetWindow();
     RefPtr<dom::Element> result;
     DOMFocusManager->MoveFocus(
         window, nullptr, nsIFocusManager::MOVEFOCUS_CARET,
         nsIFocusManager::FLAG_BYMOVEFOCUS, getter_AddRefs(result));
   }
 

--- a/accessible/generic/ImageAccessible.cpp
+++ b/accessible/generic/ImageAccessible.cpp
@@ -8,17 +8,17 @@
 #include "nsAccUtils.h"
 #include "Role.h"
 #include "AccIterator.h"
 #include "States.h"
 
 #include "imgIContainer.h"
 #include "imgIRequest.h"
 #include "nsGenericHTMLElement.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIImageLoadingContent.h"
 #include "nsIPresShell.h"
 #include "nsIServiceManager.h"
 #include "nsIPersistentProperties2.h"
 #include "nsPIDOMWindow.h"
 #include "nsIURI.h"
 
 using namespace mozilla::a11y;
@@ -101,17 +101,17 @@ bool ImageAccessible::DoAction(uint8_t a
 
   nsCOMPtr<nsIURI> uri = GetLongDescURI();
   if (!uri) return false;
 
   nsAutoCString utf8spec;
   uri->GetSpec(utf8spec);
   NS_ConvertUTF8toUTF16 spec(utf8spec);
 
-  nsIDocument* document = mContent->OwnerDoc();
+  dom::Document* document = mContent->OwnerDoc();
   nsCOMPtr<nsPIDOMWindowOuter> piWindow = document->GetWindow();
   if (!piWindow) return false;
 
   nsCOMPtr<nsPIDOMWindowOuter> tmp;
   return NS_SUCCEEDED(piWindow->Open(spec, EmptyString(), EmptyString(),
                                      /* aLoadInfo = */ nullptr,
                                      /* aForceNoOpener = */ false,
                                      getter_AddRefs(tmp)));

--- a/accessible/generic/OuterDocAccessible.cpp
+++ b/accessible/generic/OuterDocAccessible.cpp
@@ -32,19 +32,19 @@ OuterDocAccessible::OuterDocAccessible(n
 #ifdef XP_WIN
   if (DocAccessibleParent* remoteDoc = RemoteChildDoc()) {
     remoteDoc->SendParentCOMProxy();
   }
 #endif
 
   // Request document accessible for the content document to make sure it's
   // created. It will appended to outerdoc accessible children asynchronously.
-  nsIDocument* outerDoc = mContent->GetUncomposedDoc();
+  dom::Document* outerDoc = mContent->GetUncomposedDoc();
   if (outerDoc) {
-    nsIDocument* innerDoc = outerDoc->GetSubDocumentFor(mContent);
+    dom::Document* innerDoc = outerDoc->GetSubDocumentFor(mContent);
     if (innerDoc) GetAccService()->GetDocAccessible(innerDoc);
   }
 }
 
 OuterDocAccessible::~OuterDocAccessible() {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // Accessible public (DON'T add methods here)

--- a/accessible/generic/RootAccessible.cpp
+++ b/accessible/generic/RootAccessible.cpp
@@ -27,17 +27,17 @@
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/ScriptSettings.h"
 
 #include "nsIDocShellTreeItem.h"
 #include "nsIDocShellTreeOwner.h"
 #include "mozilla/dom/Event.h"
 #include "mozilla/dom/EventTarget.h"
 #include "nsIDOMXULMultSelectCntrlEl.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsIPropertyBag2.h"
 #include "nsIServiceManager.h"
 #include "nsPIDOMWindow.h"
 #include "nsIWebBrowserChrome.h"
 #include "nsReadableUtils.h"
 #include "nsFocusManager.h"
 #include "nsGlobalWindow.h"
@@ -53,17 +53,17 @@ using namespace mozilla::dom;
 ////////////////////////////////////////////////////////////////////////////////
 // nsISupports
 
 NS_IMPL_ISUPPORTS_INHERITED(RootAccessible, DocAccessible, nsIDOMEventListener)
 
 ////////////////////////////////////////////////////////////////////////////////
 // Constructor/destructor
 
-RootAccessible::RootAccessible(nsIDocument* aDocument, nsIPresShell* aPresShell)
+RootAccessible::RootAccessible(Document* aDocument, nsIPresShell* aPresShell)
     : DocAccessibleWrap(aDocument, aPresShell) {
   mType = eRootType;
 }
 
 RootAccessible::~RootAccessible() {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // Accessible
@@ -443,17 +443,17 @@ void RootAccessible::Shutdown() {
 Relation RootAccessible::RelationByType(RelationType aType) const {
   if (!mDocumentNode || aType != RelationType::EMBEDS)
     return DocAccessibleWrap::RelationByType(aType);
 
   if (nsPIDOMWindowOuter* rootWindow = mDocumentNode->GetWindow()) {
     nsCOMPtr<nsPIDOMWindowOuter> contentWindow =
         nsGlobalWindowOuter::Cast(rootWindow)->GetContent();
     if (contentWindow) {
-      nsCOMPtr<nsIDocument> contentDocumentNode = contentWindow->GetDoc();
+      RefPtr<Document> contentDocumentNode = contentWindow->GetDoc();
       if (contentDocumentNode) {
         DocAccessible* contentDocument =
             GetAccService()->GetDocAccessible(contentDocumentNode);
         if (contentDocument) return Relation(contentDocument);
       }
     }
   }
 

--- a/accessible/generic/RootAccessible.h
+++ b/accessible/generic/RootAccessible.h
@@ -6,26 +6,24 @@
 #ifndef mozilla_a11y_RootAccessible_h__
 #define mozilla_a11y_RootAccessible_h__
 
 #include "HyperTextAccessible.h"
 #include "DocAccessibleWrap.h"
 
 #include "nsIDOMEventListener.h"
 
-class nsIDocument;
-
 namespace mozilla {
 namespace a11y {
 
 class RootAccessible : public DocAccessibleWrap, public nsIDOMEventListener {
   NS_DECL_ISUPPORTS_INHERITED
 
  public:
-  RootAccessible(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  RootAccessible(dom::Document* aDocument, nsIPresShell* aPresShell);
 
   // nsIDOMEventListener
   NS_DECL_NSIDOMEVENTLISTENER
 
   // Accessible
   virtual void Shutdown() override;
   virtual mozilla::a11y::ENameValueFlag Name(nsString& aName) const override;
   virtual Relation RelationByType(RelationType aType) const override;

--- a/accessible/html/HTMLTableAccessible.cpp
+++ b/accessible/html/HTMLTableAccessible.cpp
@@ -14,17 +14,17 @@
 #include "nsTextEquivUtils.h"
 #include "Relation.h"
 #include "Role.h"
 #include "States.h"
 #include "TreeWalker.h"
 
 #include "mozilla/dom/HTMLTableElement.h"
 #include "nsIHTMLCollection.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIMutableArray.h"
 #include "nsIPersistentProperties2.h"
 #include "nsIPresShell.h"
 #include "nsITableCellLayout.h"
 #include "nsFrameSelection.h"
 #include "nsError.h"
 #include "nsArrayUtils.h"
 #include "nsComponentManagerUtils.h"

--- a/accessible/mac/DocAccessibleWrap.h
+++ b/accessible/mac/DocAccessibleWrap.h
@@ -8,16 +8,16 @@
 
 #include "DocAccessible.h"
 
 namespace mozilla {
 namespace a11y {
 
 class DocAccessibleWrap : public DocAccessible {
  public:
-  DocAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  DocAccessibleWrap(dom::Document* aDocument, nsIPresShell* aPresShell);
   virtual ~DocAccessibleWrap();
 };
 
 }  // namespace a11y
 }  // namespace mozilla
 
 #endif

--- a/accessible/mac/DocAccessibleWrap.mm
+++ b/accessible/mac/DocAccessibleWrap.mm
@@ -5,17 +5,17 @@
 
 #include "DocAccessibleWrap.h"
 
 #import "mozAccessible.h"
 
 using namespace mozilla::a11y;
 
 DocAccessibleWrap::
-  DocAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell) :
+  DocAccessibleWrap(mozilla::dom::Document* aDocument, nsIPresShell* aPresShell) :
   DocAccessible(aDocument, aPresShell)
 {
 }
 
 DocAccessibleWrap::~DocAccessibleWrap()
 {
 }
 

--- a/accessible/mac/RootAccessibleWrap.h
+++ b/accessible/mac/RootAccessibleWrap.h
@@ -12,17 +12,17 @@
 
 #include "RootAccessible.h"
 
 namespace mozilla {
 namespace a11y {
 
 class RootAccessibleWrap : public RootAccessible {
  public:
-  RootAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  RootAccessibleWrap(dom::Document* aDocument, nsIPresShell* aPresShell);
   virtual ~RootAccessibleWrap();
 
   Class GetNativeType();
 
   // let's our native accessible get in touch with the
   // native cocoa view that is our accessible parent.
   void GetNativeWidget(void** aOutView);
 };

--- a/accessible/mac/RootAccessibleWrap.mm
+++ b/accessible/mac/RootAccessibleWrap.mm
@@ -11,17 +11,17 @@
 #include "nsObjCExceptions.h"
 #include "nsIFrame.h"
 #include "nsView.h"
 #include "nsIWidget.h"
 
 using namespace mozilla::a11y;
 
 RootAccessibleWrap::
-  RootAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell) :
+  RootAccessibleWrap(mozilla::dom::Document* aDocument, nsIPresShell* aPresShell) :
   RootAccessible(aDocument, aPresShell)
 {
 }
 
 RootAccessibleWrap::~RootAccessibleWrap()
 {
 }
 

--- a/accessible/windows/msaa/AccessibleWrap.cpp
+++ b/accessible/windows/msaa/AccessibleWrap.cpp
@@ -476,17 +476,17 @@ AccessibleWrap::get_accRole(
     nsAutoString roleString;
     // Try the role attribute.
     content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::role,
                                   roleString);
 
     if (roleString.IsEmpty()) {
       // No role attribute (or it is an empty string).
       // Use the tag name.
-      nsIDocument* document = content->GetUncomposedDoc();
+      dom::Document* document = content->GetUncomposedDoc();
       if (!document) return E_FAIL;
 
       dom::NodeInfo* nodeInfo = content->NodeInfo();
       nodeInfo->GetName(roleString);
 
       // Only append name space if different from that of current document.
       if (!nodeInfo->NamespaceEquals(document->GetDefaultNamespaceID())) {
         nsAutoString nameSpaceURI;

--- a/accessible/windows/msaa/DocAccessibleWrap.cpp
+++ b/accessible/windows/msaa/DocAccessibleWrap.cpp
@@ -20,17 +20,17 @@
 
 using namespace mozilla;
 using namespace mozilla::a11y;
 
 ////////////////////////////////////////////////////////////////////////////////
 // DocAccessibleWrap
 ////////////////////////////////////////////////////////////////////////////////
 
-DocAccessibleWrap::DocAccessibleWrap(nsIDocument* aDocument,
+DocAccessibleWrap::DocAccessibleWrap(dom::Document* aDocument,
                                      nsIPresShell* aPresShell)
     : DocAccessible(aDocument, aPresShell), mHWND(nullptr) {}
 
 DocAccessibleWrap::~DocAccessibleWrap() {}
 
 IMPL_IUNKNOWN_QUERY_HEAD(DocAccessibleWrap)
 if (aIID == IID_ISimpleDOMDocument) {
   statistics::ISimpleDOMUsed();

--- a/accessible/windows/msaa/DocAccessibleWrap.h
+++ b/accessible/windows/msaa/DocAccessibleWrap.h
@@ -9,17 +9,17 @@
 
 #include "DocAccessible.h"
 
 namespace mozilla {
 namespace a11y {
 
 class DocAccessibleWrap : public DocAccessible {
  public:
-  DocAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  DocAccessibleWrap(dom::Document* aDocument, nsIPresShell* aPresShell);
   virtual ~DocAccessibleWrap();
 
   DECL_IUNKNOWN_INHERITED
 
   // IAccessible
 
   // Override get_accParent for e10s
   virtual /* [id][propget] */ HRESULT STDMETHODCALLTYPE get_accParent(

--- a/accessible/windows/msaa/RootAccessibleWrap.cpp
+++ b/accessible/windows/msaa/RootAccessibleWrap.cpp
@@ -10,17 +10,17 @@
 #include "nsCoreUtils.h"
 #include "nsWinUtils.h"
 
 using namespace mozilla::a11y;
 
 ////////////////////////////////////////////////////////////////////////////////
 // Constructor/destructor
 
-RootAccessibleWrap::RootAccessibleWrap(nsIDocument* aDocument,
+RootAccessibleWrap::RootAccessibleWrap(dom::Document* aDocument,
                                        nsIPresShell* aPresShell)
     : RootAccessible(aDocument, aPresShell), mOuter(&mInternalUnknown) {}
 
 RootAccessibleWrap::~RootAccessibleWrap() {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // Aggregated IUnknown
 HRESULT

--- a/accessible/windows/msaa/RootAccessibleWrap.h
+++ b/accessible/windows/msaa/RootAccessibleWrap.h
@@ -9,17 +9,17 @@
 #include "mozilla/mscom/Aggregation.h"
 #include "RootAccessible.h"
 
 namespace mozilla {
 namespace a11y {
 
 class RootAccessibleWrap : public RootAccessible {
  public:
-  RootAccessibleWrap(nsIDocument* aDocument, nsIPresShell* aPresShell);
+  RootAccessibleWrap(dom::Document* aDocument, nsIPresShell* aPresShell);
   virtual ~RootAccessibleWrap();
 
   // RootAccessible
   virtual void DocumentActivated(DocAccessible* aDocument);
 
   /**
    * This method enables a RootAccessibleWrap to be wrapped by a
    * LazyInstantiator.

--- a/accessible/windows/msaa/nsWinUtils.cpp
+++ b/accessible/windows/msaa/nsWinUtils.cpp
@@ -12,17 +12,17 @@
 #include "nsAccessibilityService.h"
 #include "nsCoreUtils.h"
 
 #include "mozilla/a11y/DocAccessibleParent.h"
 #include "mozilla/Preferences.h"
 #include "nsArrayUtils.h"
 #include "nsIArray.h"
 #include "nsICSSDeclaration.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIDocShellTreeItem.h"
 #include "mozilla/dom/Element.h"
 #include "nsXULAppAPI.h"
 #include "ProxyWrappers.h"
 
 using namespace mozilla;
 using namespace mozilla::a11y;
 using mozilla::dom::Element;

--- a/accessible/xpcom/xpcAccessibilityService.cpp
+++ b/accessible/xpcom/xpcAccessibilityService.cpp
@@ -187,21 +187,18 @@ xpcAccessibilityService::GetAccessibleFr
 
   // Search for an accessible in each of our per document accessible object
   // caches. If we don't find it, and the given node is itself a document, check
   // our cache of document accessibles (document cache). Note usually shutdown
   // document accessibles are not stored in the document cache, however an
   // "unofficially" shutdown document (i.e. not from DocManager) can still
   // exist in the document cache.
   Accessible* accessible = accService->FindAccessibleInCache(aNode);
-  if (!accessible) {
-    nsCOMPtr<nsIDocument> document(do_QueryInterface(aNode));
-    if (document) {
-      accessible = mozilla::a11y::GetExistingDocAccessible(document);
-    }
+  if (!accessible && aNode->IsDocument()) {
+    accessible = mozilla::a11y::GetExistingDocAccessible(aNode->AsDocument());
   }
 
   NS_IF_ADDREF(*aAccessible = ToXPC(accessible));
   return NS_OK;
 }
 
 NS_IMETHODIMP
 xpcAccessibilityService::CreateAccessiblePivot(nsIAccessible* aRoot,

--- a/accessible/xpcom/xpcAccessibleDocument.cpp
+++ b/accessible/xpcom/xpcAccessibleDocument.cpp
@@ -71,17 +71,17 @@ NS_IMETHODIMP
 xpcAccessibleDocument::GetDocType(nsAString& aType) {
   if (!Intl()) return NS_ERROR_FAILURE;
 
   Intl()->DocType(aType);
   return NS_OK;
 }
 
 NS_IMETHODIMP
-xpcAccessibleDocument::GetDOMDocument(nsIDocument** aDOMDocument) {
+xpcAccessibleDocument::GetDOMDocument(dom::Document** aDOMDocument) {
   NS_ENSURE_ARG_POINTER(aDOMDocument);
   *aDOMDocument = nullptr;
 
   if (!Intl()) return NS_ERROR_FAILURE;
 
   if (Intl()->DocumentNode()) NS_ADDREF(*aDOMDocument = Intl()->DocumentNode());
 
   return NS_OK;

--- a/accessible/xpcom/xpcAccessibleDocument.h
+++ b/accessible/xpcom/xpcAccessibleDocument.h
@@ -35,17 +35,17 @@ class xpcAccessibleDocument : public xpc
 
   NS_DECL_ISUPPORTS_INHERITED
 
   // nsIAccessibleDocument
   NS_IMETHOD GetURL(nsAString& aURL) final;
   NS_IMETHOD GetTitle(nsAString& aTitle) final;
   NS_IMETHOD GetMimeType(nsAString& aType) final;
   NS_IMETHOD GetDocType(nsAString& aType) final;
-  NS_IMETHOD GetDOMDocument(nsIDocument** aDOMDocument) final;
+  NS_IMETHOD GetDOMDocument(dom::Document** aDOMDocument) final;
   NS_IMETHOD GetWindow(mozIDOMWindowProxy** aDOMWindow) final;
   NS_IMETHOD GetParentDocument(nsIAccessibleDocument** aDocument) final;
   NS_IMETHOD GetChildDocumentCount(uint32_t* aCount) final;
   NS_IMETHOD GetChildDocumentAt(uint32_t aIndex,
                                 nsIAccessibleDocument** aDocument) final;
   NS_IMETHOD GetVirtualCursor(nsIAccessiblePivot** aVirtualCursor) final;
 
   /**

--- a/accessible/xul/XULElementAccessibles.cpp
+++ b/accessible/xul/XULElementAccessibles.cpp
@@ -201,16 +201,16 @@ uint32_t XULLinkAccessible::EndOffset() 
 already_AddRefed<nsIURI> XULLinkAccessible::AnchorURIAt(
     uint32_t aAnchorIndex) const {
   if (aAnchorIndex != 0) return nullptr;
 
   nsAutoString href;
   mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::href, href);
 
   nsCOMPtr<nsIURI> baseURI = mContent->GetBaseURI();
-  nsIDocument* document = mContent->OwnerDoc();
+  dom::Document* document = mContent->OwnerDoc();
 
   nsCOMPtr<nsIURI> anchorURI;
   NS_NewURI(getter_AddRefs(anchorURI), href,
             document->GetDocumentCharacterSet(), baseURI);
 
   return anchorURI.forget();
 }

--- a/accessible/xul/XULTabAccessible.cpp
+++ b/accessible/xul/XULTabAccessible.cpp
@@ -7,17 +7,17 @@
 
 #include "ARIAMap.h"
 #include "nsAccUtils.h"
 #include "Relation.h"
 #include "Role.h"
 #include "States.h"
 
 // NOTE: alphabetically ordered
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIDOMXULSelectCntrlEl.h"
 #include "nsIDOMXULSelectCntrlItemEl.h"
 #include "nsIDOMXULRelatedElement.h"
 #include "nsXULElement.h"
 
 #include "mozilla/dom/BindingDeclarations.h"
 
 using namespace mozilla::a11y;

--- a/browser/components/aboutconfig/content/aboutconfig.js
+++ b/browser/components/aboutconfig/content/aboutconfig.js
@@ -5,16 +5,45 @@
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/Preferences.jsm");
 
 let gDefaultBranch = Services.prefs.getDefaultBranch("");
 let gPrefArray;
 let gPrefRowInEdit;
 let gPrefInEdit;
 
+class PrefRow {
+  constructor(name) {
+    this.name = name;
+    this.refreshValue();
+  }
+
+  refreshValue() {
+    this.hasUserValue = Services.prefs.prefHasUserValue(this.name);
+    this.hasDefaultValue = this.hasUserValue ? prefHasDefaultValue(this.name)
+                                             : true;
+    this.isLocked = Services.prefs.prefIsLocked(this.name);
+
+    try {
+      // This can throw for locked preferences without a default value.
+      this.value = Preferences.get(this.name);
+      // We don't know which preferences should be read using getComplexValue,
+      // so we use a heuristic to determine if this is a localized preference.
+      if (!this.hasUserValue &&
+          /^chrome:\/\/.+\/locale\/.+\.properties/.test(this.value)) {
+        // This can throw if there is no value in the localized files.
+        this.value = Services.prefs.getComplexValue(this.name,
+          Ci.nsIPrefLocalizedString).data;
+      }
+    } catch (ex) {
+      this.value = "";
+    }
+  }
+}
+
 function getPrefName(prefRow) {
   return prefRow.getAttribute("aria-label");
 }
 
 document.addEventListener("DOMContentLoaded", () => {
   if (!Preferences.get("browser.aboutConfig.showWarning")) {
     loadPrefs();
   }
@@ -33,38 +62,17 @@ function loadPrefs() {
   search.type = "text";
   search.id = "search";
   document.l10n.setAttributes(search, "about-config-search");
   document.body.appendChild(search);
   let prefs = document.createElement("table");
   prefs.id = "prefs";
   document.body.appendChild(prefs);
 
-  gPrefArray = Services.prefs.getChildList("").map(function(name) {
-    let hasUserValue = Services.prefs.prefHasUserValue(name);
-    let pref = {
-      name,
-      hasUserValue,
-      hasDefaultValue: hasUserValue ? prefHasDefaultValue(name) : true,
-      isLocked: Services.prefs.prefIsLocked(name),
-    };
-    // Try in case it's a localized string or locked user added pref
-    // If an execption is thrown the pref value is set to the empty string.
-    try {
-      // Throws an exception in case locked user added pref without default value
-      pref.value = Preferences.get(name);
-      // Throws an exception if there is no equivalent value in the localized files for the pref.
-      if (!pref.hasUserValue && /^chrome:\/\/.+\/locale\/.+\.properties/.test(pref.value)) {
-        pref.value = Services.prefs.getComplexValue(name, Ci.nsIPrefLocalizedString).data;
-      }
-    } catch (ex) {
-      pref.value = "";
-    }
-    return pref;
-  });
+  gPrefArray = Services.prefs.getChildList("").map(name => new PrefRow(name));
 
   gPrefArray.sort((a, b) => a.name > b.name);
 
   search.addEventListener("keypress", e => {
     if (e.key == "Enter") {
       filterPrefs();
     }
   });
@@ -75,18 +83,17 @@ function loadPrefs() {
     }
     let prefRow = event.target.closest("tr");
     let prefName = getPrefName(prefRow);
     let pref = gPrefArray.find(p => p.name == prefName);
     let button = event.target.closest("button");
     if (button.classList.contains("button-reset")) {
       // Reset pref and update gPrefArray.
       Services.prefs.clearUserPref(prefName);
-      pref.value = Preferences.get(prefName);
-      pref.hasUserValue = false;
+      pref.refreshValue();
       // Update UI.
       prefRow.textContent = "";
       prefRow.classList.remove("has-user-value");
       prefRow.appendChild(getPrefRow(pref));
       prefRow.querySelector("td.cell-edit").firstChild.focus();
     } else if (button.classList.contains("add-true")) {
       addNewPref(prefRow.firstChild.innerHTML, true);
     } else if (button.classList.contains("add-false")) {
@@ -97,18 +104,17 @@ function loadPrefs() {
         button.classList.contains("add-Number") ? 0 : "");
       prefRow = [...prefs.getElementsByTagName("tr")]
         .find(row => row.querySelector("td").textContent == prefName);
       startEditingPref(prefRow, gPrefArray.find(p => p.name == prefName));
       prefRow.querySelector("td.cell-value").firstChild.firstChild.focus();
     } else if (button.classList.contains("button-toggle")) {
       // Toggle the pref and update gPrefArray.
       Services.prefs.setBoolPref(prefName, !pref.value);
-      pref.value = !pref.value;
-      pref.hasUserValue = Services.prefs.prefHasUserValue(pref.name);
+      pref.refreshValue();
       // Update UI.
       prefRow.textContent = "";
       if (pref.hasUserValue) {
         prefRow.classList.add("has-user-value");
       } else {
         prefRow.classList.remove("has-user-value");
       }
       prefRow.appendChild(getPrefRow(pref));
@@ -291,18 +297,17 @@ function endEditingPref(row) {
     }
     newValue = numberValue;
     Services.prefs.setIntPref(name, newValue);
   } else {
     Services.prefs.setStringPref(name, newValue);
   }
 
   // Update gPrefArray.
-  gPrefInEdit.value = newValue;
-  gPrefInEdit.hasUserValue = Services.prefs.prefHasUserValue(name);
+  gPrefInEdit.refreshValue();
   // Update UI.
   row.textContent = "";
   if (gPrefInEdit.hasUserValue) {
     row.classList.add("has-user-value");
   } else {
     row.classList.remove("has-user-value");
   }
   row.appendChild(getPrefRow(gPrefInEdit));
@@ -322,17 +327,12 @@ function prefHasDefaultValue(name) {
         return true;
     }
   } catch (ex) {}
   return false;
 }
 
 function addNewPref(name, value) {
   Preferences.set(name, value);
-  gPrefArray.push({
-    name,
-    value,
-    hasUserValue: true,
-    hasDefaultValue: false,
-  });
+  gPrefArray.push(new PrefRow(name));
   gPrefArray.sort((a, b) => a.name > b.name);
   filterPrefs();
 }

--- a/browser/components/aboutconfig/test/browser/browser_basic.js
+++ b/browser/components/aboutconfig/test/browser/browser_basic.js
@@ -1,51 +1,49 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 add_task(async function setup() {
   await SpecialPowers.pushPrefEnv({
     set: [
-      ["random.user.pref", "chrome://test/locale/testing.properties"],
+      ["test.aboutconfig.userValueLikeLocalized",
+       "chrome://test/locale/testing.properties"],
     ],
   });
 });
 
 add_task(async function test_load_title() {
   await AboutConfigTest.withNewTab(async function() {
     Assert.equal(this.document.title, "about:config");
   });
 });
 
 add_task(async function test_load_settings() {
   await AboutConfigTest.withNewTab(async function() {
     // Test if page contains elements.
-    Assert.ok(this.getRow("plugins.testmode"));
-    Assert.ok(this.getRow("dom.vr.enabled"));
-    Assert.ok(this.getRow("accessibility.AOM.enabled"));
+    Assert.equal(this.getRow(PREF_NUMBER_DEFAULT_ZERO).value, 0);
+    Assert.equal(this.getRow(PREF_STRING_DEFAULT_EMPTY).value, "");
 
     // Test if the modified state is displayed for the right prefs.
-    let prefArray = Services.prefs.getChildList("");
-    let nameOfEdited = prefArray.find(
-      name => Services.prefs.prefHasUserValue(name));
-    let nameOfDefault = prefArray.find(
-      name => !Services.prefs.prefHasUserValue(name));
-    Assert.ok(!this.getRow(nameOfDefault).hasClass("has-user-value"));
-    Assert.ok(this.getRow(nameOfEdited).hasClass("has-user-value"));
+    Assert.ok(!this.getRow(PREF_BOOLEAN_DEFAULT_TRUE)
+                   .hasClass("has-user-value"));
+    Assert.ok(this.getRow(PREF_BOOLEAN_USERVALUE_TRUE)
+                  .hasClass("has-user-value"));
 
-    // Test to see if values are localized.
+    // Test to see if values are localized, sampling from different files. If
+    // any of these are removed or their value changes, just update the value
+    // here or point to a different preference in the same file.
     Assert.equal(this.getRow("font.language.group").value, "x-western");
     Assert.equal(this.getRow("intl.ellipsis").value, "\u2026");
     Assert.equal(
       this.getRow("gecko.handlerService.schemes.mailto.1.uriTemplate").value,
       "https://mail.google.com/mail/?extsrc=mailto&url=%s");
 
     // Test to see if user created value is not empty string when it matches
     // /^chrome:\/\/.+\/locale\/.+\.properties/.
-    Assert.equal(this.getRow("random.user.pref").value,
+    Assert.equal(this.getRow("test.aboutconfig.userValueLikeLocalized").value,
       "chrome://test/locale/testing.properties");
 
     // Test to see if empty string when value matches
     // /^chrome:\/\/.+\/locale\/.+\.properties/ and an exception is thrown.
-    Assert.equal(this.getRow("gecko.handlerService.schemes.irc.1.name").value,
-      "");
+    Assert.equal(this.getRow(PREF_STRING_LOCALIZED_MISSING).value, "");
   });
 });

--- a/browser/components/aboutconfig/test/browser/browser_edit.js
+++ b/browser/components/aboutconfig/test/browser/browser_edit.js
@@ -6,19 +6,19 @@ add_task(async function setup() {
     set: [
       ["test.aboutconfig.modify.boolean", true],
       ["test.aboutconfig.modify.number", 1337],
       ["test.aboutconfig.modify.string", "the answer to the life the universe and everything"],
     ],
   });
 
   registerCleanupFunction(() => {
-    Services.prefs.clearUserPref("accessibility.typeaheadfind.autostart");
-    Services.prefs.clearUserPref("accessibility.typeaheadfind.soundURL");
-    Services.prefs.clearUserPref("accessibility.typeaheadfind.casesensitive");
+    Services.prefs.clearUserPref(PREF_BOOLEAN_DEFAULT_TRUE);
+    Services.prefs.clearUserPref(PREF_NUMBER_DEFAULT_ZERO);
+    Services.prefs.clearUserPref(PREF_STRING_DEFAULT_EMPTY);
   });
 });
 
 add_task(async function test_add_user_pref() {
   await AboutConfigTest.withNewTab(async function() {
     Assert.ok(!Services.prefs.getChildList("").find(pref => pref == "testPref"));
 
     for (let [buttonSelector, expectedValue] of [
@@ -35,101 +35,112 @@ add_task(async function test_add_user_pr
     }
   });
 });
 
 add_task(async function test_delete_user_pref() {
   Services.prefs.setBoolPref("userAddedPref", true);
   await AboutConfigTest.withNewTab(async function() {
     let row = this.getRow("userAddedPref");
-    row.element.lastChild.lastChild.click();
+    row.resetColumnButton.click();
     Assert.ok(!this.getRow("userAddedPref"));
     Assert.ok(!Services.prefs.getChildList("").includes("userAddedPref"));
 
     // Search for nothing to test gPrefArray
     this.search();
     Assert.ok(!this.getRow("userAddedPref"));
   });
 });
 
 add_task(async function test_reset_user_pref() {
-  await SpecialPowers.pushPrefEnv({"set": [["browser.autofocus", false]]});
+  await SpecialPowers.pushPrefEnv({
+    "set": [
+      [PREF_BOOLEAN_DEFAULT_TRUE, false],
+      [PREF_STRING_LOCALIZED_MISSING, "user-value"],
+    ],
+  });
 
   await AboutConfigTest.withNewTab(async function() {
-    let testPref = "browser.autofocus";
     // Click reset.
-    let row = this.getRow(testPref);
-    row.element.lastChild.lastChild.click();
+    let row = this.getRow(PREF_BOOLEAN_DEFAULT_TRUE);
+    row.resetColumnButton.click();
     // Check new layout and reset.
     Assert.ok(!row.hasClass("has-user-value"));
-    Assert.equal(row.element.lastChild.childNodes.length, 0);
-    Assert.ok(!Services.prefs.prefHasUserValue(testPref));
-    Assert.equal(this.getRow(testPref).value, "" + Preferences.get(testPref));
+    Assert.ok(!row.resetColumnButton);
+    Assert.ok(!Services.prefs.prefHasUserValue(PREF_BOOLEAN_DEFAULT_TRUE));
+    Assert.equal(this.getRow(PREF_BOOLEAN_DEFAULT_TRUE).value, "true");
 
     // Search for nothing to test gPrefArray
     this.search();
-    row = this.getRow(testPref);
+    row = this.getRow(PREF_BOOLEAN_DEFAULT_TRUE);
     Assert.ok(!row.hasClass("has-user-value"));
-    Assert.equal(row.element.lastChild.childNodes.length, 0);
-    Assert.equal(this.getRow(testPref).value, "" + Preferences.get(testPref));
+    Assert.ok(!row.resetColumnButton);
+    Assert.equal(this.getRow(PREF_BOOLEAN_DEFAULT_TRUE).value, "true");
+
+    // Clicking reset on a localized preference without a corresponding value.
+    row = this.getRow(PREF_STRING_LOCALIZED_MISSING);
+    Assert.equal(row.value, "user-value");
+    row.resetColumnButton.click();
+    // Check new layout and reset.
+    Assert.ok(!row.hasClass("has-user-value"));
+    Assert.ok(!row.resetColumnButton);
+    Assert.ok(!Services.prefs.prefHasUserValue(PREF_STRING_LOCALIZED_MISSING));
+    Assert.equal(this.getRow(PREF_STRING_LOCALIZED_MISSING).value, "");
   });
 });
 
 add_task(async function test_modify() {
   await AboutConfigTest.withNewTab(async function() {
     // Test toggle for boolean prefs.
     for (let nameOfBoolPref of [
       "test.aboutconfig.modify.boolean",
-      "accessibility.typeaheadfind.autostart",
+      PREF_BOOLEAN_DEFAULT_TRUE,
     ]) {
       let row = this.getRow(nameOfBoolPref);
       // Do this a two times to reset the pref.
       for (let i = 0; i < 2; i++) {
-        row.querySelector("td.cell-edit").firstChild.click();
+        row.editColumnButton.click();
         // Check new layout and saving in backend.
         Assert.equal(this.getRow(nameOfBoolPref).value,
           "" + Preferences.get(nameOfBoolPref));
         let prefHasUserValue = Services.prefs.prefHasUserValue(nameOfBoolPref);
         Assert.equal(row.hasClass("has-user-value"), prefHasUserValue);
-        Assert.equal(row.element.lastChild.childNodes.length > 0, prefHasUserValue);
+        Assert.equal(!!row.resetColumnButton, prefHasUserValue);
       }
     }
 
     // Test abort of edit by starting with string and continuing with editing Int pref.
     let row = this.getRow("test.aboutconfig.modify.string");
-    row.querySelector("td.cell-edit").firstChild.click();
-    row.querySelector("td.cell-value").firstChild.firstChild.value = "test";
+    row.editColumnButton.click();
+    row.valueInput.value = "test";
     let intRow = this.getRow("test.aboutconfig.modify.number");
-    intRow.querySelector("td.cell-edit").firstChild.click();
-    Assert.equal(intRow.querySelector("td.cell-value").firstChild.firstChild.value,
+    intRow.editColumnButton.click();
+    Assert.equal(intRow.valueInput.value,
       Preferences.get("test.aboutconfig.modify.number"));
-    Assert.equal(this.getRow("test.aboutconfig.modify.string").value,
-      "" + Preferences.get("test.aboutconfig.modify.string"));
-    Assert.equal(row.querySelector("td.cell-value").textContent,
-      Preferences.get("test.aboutconfig.modify.string"));
+    Assert.ok(!row.valueInput);
+    Assert.equal(row.value, Preferences.get("test.aboutconfig.modify.string"));
 
     // Test regex check for Int pref.
-    intRow.querySelector("td.cell-value").firstChild.firstChild.value += "a";
-    intRow.querySelector("td.cell-edit").firstChild.click();
-    Assert.ok(!intRow.querySelector("td.cell-value").firstChild.firstChild.checkValidity());
+    intRow.valueInput.value += "a";
+    intRow.editColumnButton.click();
+    Assert.ok(!intRow.valueInput.checkValidity());
 
     // Test correct saving and DOM-update.
     for (let prefName of [
       "test.aboutconfig.modify.string",
       "test.aboutconfig.modify.number",
-      "accessibility.typeaheadfind.soundURL",
-      "accessibility.typeaheadfind.casesensitive",
+      PREF_NUMBER_DEFAULT_ZERO,
+      PREF_STRING_DEFAULT_EMPTY,
     ]) {
       row = this.getRow(prefName);
       // Activate edit and check displaying.
-      row.querySelector("td.cell-edit").firstChild.click();
-      Assert.equal(row.querySelector("td.cell-value").firstChild.firstChild.value,
-        Preferences.get(prefName));
-      row.querySelector("td.cell-value").firstChild.firstChild.value = "42";
+      row.editColumnButton.click();
+      Assert.equal(row.valueInput.value, Preferences.get(prefName));
+      row.valueInput.value = "42";
       // Save and check saving.
-      row.querySelector("td.cell-edit").firstChild.click();
+      row.editColumnButton.click();
       Assert.equal(row.value, "" + Preferences.get(prefName));
       let prefHasUserValue = Services.prefs.prefHasUserValue(prefName);
-      Assert.equal(row.element.lastChild.childNodes.length > 0, prefHasUserValue);
+      Assert.equal(!!row.resetColumnButton, prefHasUserValue);
       Assert.equal(row.hasClass("has-user-value"), prefHasUserValue);
     }
   });
 });

--- a/browser/components/aboutconfig/test/browser/browser_locked.js
+++ b/browser/components/aboutconfig/test/browser/browser_locked.js
@@ -1,51 +1,54 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
+const PREF_STRING_NO_DEFAULT = "test.aboutconfig.a";
+
 add_task(async function setup() {
   await SpecialPowers.pushPrefEnv({
     set: [
-      ["test.aboutconfig.a", "some value"],
+      [PREF_STRING_NO_DEFAULT, "some value"],
     ],
   });
 });
 
 add_task(async function test_locked() {
   registerCleanupFunction(() => {
-    Services.prefs.unlockPref("browser.search.searchEnginesURL");
-    Services.prefs.unlockPref("test.aboutconfig.a");
-    Services.prefs.unlockPref("accessibility.AOM.enabled");
+    Services.prefs.unlockPref(PREF_STRING_DEFAULT_NOTEMPTY);
+    Services.prefs.unlockPref(PREF_BOOLEAN_DEFAULT_TRUE);
+    Services.prefs.unlockPref(PREF_STRING_NO_DEFAULT);
   });
 
-  Services.prefs.lockPref("browser.search.searchEnginesURL");
-  Services.prefs.lockPref("test.aboutconfig.a");
-  Services.prefs.lockPref("accessibility.AOM.enabled");
+  Services.prefs.lockPref(PREF_STRING_DEFAULT_NOTEMPTY);
+  Services.prefs.lockPref(PREF_BOOLEAN_DEFAULT_TRUE);
+  Services.prefs.lockPref(PREF_STRING_NO_DEFAULT);
+
   await AboutConfigTest.withNewTab(async function() {
     // Test locked default string pref.
-    let lockedPref = this.getRow("browser.search.searchEnginesURL");
+    let lockedPref = this.getRow(PREF_STRING_DEFAULT_NOTEMPTY);
     Assert.ok(lockedPref.hasClass("locked"));
-    Assert.equal(lockedPref.value, "https://addons.mozilla.org/%LOCALE%/firefox/search-engines/");
-    Assert.ok(lockedPref.firstButton.classList.contains("button-edit"));
-    Assert.ok(lockedPref.firstButton.disabled);
+    Assert.equal(lockedPref.value, PREF_STRING_DEFAULT_NOTEMPTY_VALUE);
+    Assert.ok(lockedPref.editColumnButton.classList.contains("button-edit"));
+    Assert.ok(lockedPref.editColumnButton.disabled);
 
     // Test locked default boolean pref.
-    lockedPref = this.getRow("accessibility.AOM.enabled");
+    lockedPref = this.getRow(PREF_BOOLEAN_DEFAULT_TRUE);
     Assert.ok(lockedPref.hasClass("locked"));
-    Assert.equal(lockedPref.value, "false");
-    Assert.ok(lockedPref.firstButton.classList.contains("button-toggle"));
-    Assert.ok(lockedPref.firstButton.disabled);
+    Assert.equal(lockedPref.value, "true");
+    Assert.ok(lockedPref.editColumnButton.classList.contains("button-toggle"));
+    Assert.ok(lockedPref.editColumnButton.disabled);
 
     // Test locked user added pref.
-    lockedPref = this.getRow("test.aboutconfig.a");
+    lockedPref = this.getRow(PREF_STRING_NO_DEFAULT);
     Assert.ok(lockedPref.hasClass("locked"));
     Assert.equal(lockedPref.value, "");
-    Assert.ok(lockedPref.firstButton.classList.contains("button-edit"));
-    Assert.ok(lockedPref.firstButton.disabled);
+    Assert.ok(lockedPref.editColumnButton.classList.contains("button-edit"));
+    Assert.ok(lockedPref.editColumnButton.disabled);
 
-    // Test pref not locked
-    let unlockedPref = this.getRow("accessibility.indicator.enabled");
+    // Test pref not locked.
+    let unlockedPref = this.getRow(PREF_BOOLEAN_USERVALUE_TRUE);
     Assert.ok(!unlockedPref.hasClass("locked"));
-    Assert.equal(unlockedPref.value, "false");
-    Assert.ok(unlockedPref.firstButton.classList.contains("button-toggle"));
-    Assert.ok(!unlockedPref.firstButton.disabled);
+    Assert.equal(unlockedPref.value, "true");
+    Assert.ok(unlockedPref.editColumnButton.classList.contains("button-toggle"));
+    Assert.ok(!unlockedPref.editColumnButton.disabled);
   });
 });

--- a/browser/components/aboutconfig/test/browser/browser_search.js
+++ b/browser/components/aboutconfig/test/browser/browser_search.js
@@ -9,17 +9,16 @@ add_task(async function setup() {
       ["test.aboutconfig.b", "test value 3"],
     ],
   });
 });
 
 add_task(async function test_search() {
   await AboutConfigTest.withNewTab(async function() {
     let prefArray = Services.prefs.getChildList("");
-    await this.document.querySelector("button").click();
 
     // The total number of preferences may change at any time because of
     // operations running in the background, so we only test approximately.
     // The change in count would be because of one or two added preferences,
     // but we tolerate a difference of up to 50 preferences just to be safe.
     // We want thousands of prefs instead of a few dozen that are filtered.
     Assert.greater(this.rows.length, prefArray.length - 50);
 

--- a/browser/components/aboutconfig/test/browser/head.js
+++ b/browser/components/aboutconfig/test/browser/head.js
@@ -1,15 +1,27 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 ChromeUtils.import("resource://gre/modules/Preferences.jsm", this);
 
+// List of default preferences that can be used for tests, chosen because they
+// have little or no side-effects when they are modified for a brief time. If
+// any of these preferences are removed or their default state changes, just
+// update the constant to point to a different preference with the same default.
+const PREF_BOOLEAN_DEFAULT_TRUE = "accessibility.typeaheadfind.manual";
+const PREF_BOOLEAN_USERVALUE_TRUE = "browser.dom.window.dump.enabled";
+const PREF_NUMBER_DEFAULT_ZERO = "accessibility.typeaheadfind.casesensitive";
+const PREF_STRING_DEFAULT_EMPTY = "browser.helperApps.neverAsk.openFile";
+const PREF_STRING_DEFAULT_NOTEMPTY = "accessibility.typeaheadfind.soundURL";
+const PREF_STRING_DEFAULT_NOTEMPTY_VALUE = "beep";
+const PREF_STRING_LOCALIZED_MISSING = "gecko.handlerService.schemes.irc.1.name";
+
 class AboutConfigRowTest {
   constructor(element) {
     this.element = element;
   }
 
   querySelector(selector) {
     return this.element.querySelector(selector);
   }
@@ -17,18 +29,36 @@ class AboutConfigRowTest {
   get name() {
     return this.querySelector("td").textContent;
   }
 
   get value() {
     return this.querySelector("td.cell-value").textContent;
   }
 
-  get firstButton() {
-    return this.querySelector("button");
+  /**
+   * Text input field when the row is in edit mode.
+   */
+  get valueInput() {
+    return this.querySelector("td.cell-value input");
+  }
+
+  /**
+   * This is normally "edit" or "toggle" based on the preference type, or "save"
+   * when the row is in edit mode.
+   */
+  get editColumnButton() {
+    return this.querySelector("td.cell-edit > button");
+  }
+
+  /**
+   * This can be "reset" or "delete" based on whether a default exists.
+   */
+  get resetColumnButton() {
+    return this.querySelector("td:last-child > button");
   }
 
   hasClass(className) {
     return this.element.classList.contains(className);
   }
 }
 
 class AboutConfigTest {

--- a/browser/components/shell/nsMacShellService.cpp
+++ b/browser/components/shell/nsMacShellService.cpp
@@ -1,16 +1,16 @@
 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsDirectoryServiceDefs.h"
 #include "nsIImageLoadingContent.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIContent.h"
 #include "nsILocalFileMac.h"
 #include "nsIObserverService.h"
 #include "nsIPrefService.h"
 #include "nsIServiceManager.h"
 #include "nsIStringBundle.h"
 #include "nsIURL.h"
 #include "nsIWebBrowserPersist.h"

--- a/browser/components/tests/browser/browser.ini
+++ b/browser/components/tests/browser/browser.ini
@@ -1,10 +1,9 @@
 [DEFAULT]
 
 [browser_bug538331.js]
 skip-if = !updater
 reason = test depends on update channel
 [browser_contentpermissionprompt.js]
 [browser_default_bookmark_toolbar_visibility.js]
 [browser_initial_tab_remoteType.js]
-skip-if = verify && !debug && os == 'mac' # Bug 1514778
 [browser_urlbar_matchBuckets_migration60.js]

--- a/caps/BasePrincipal.cpp
+++ b/caps/BasePrincipal.cpp
@@ -180,17 +180,17 @@ BasePrincipal::SetCsp(nsIContentSecurity
     return NS_ERROR_ALREADY_INITIALIZED;
   }
 
   mCSP = aCsp;
   return NS_OK;
 }
 
 NS_IMETHODIMP
-BasePrincipal::EnsureCSP(nsIDocument* aDocument,
+BasePrincipal::EnsureCSP(dom::Document* aDocument,
                          nsIContentSecurityPolicy** aCSP) {
   if (mCSP) {
     // if there is a CSP already associated with this principal
     // then just return that - do not overwrite it!!!
     NS_IF_ADDREF(*aCSP = mCSP);
     return NS_OK;
   }
 
@@ -208,17 +208,17 @@ BasePrincipal::EnsureCSP(nsIDocument* aD
 
 NS_IMETHODIMP
 BasePrincipal::GetPreloadCsp(nsIContentSecurityPolicy** aPreloadCSP) {
   NS_IF_ADDREF(*aPreloadCSP = mPreloadCSP);
   return NS_OK;
 }
 
 NS_IMETHODIMP
-BasePrincipal::EnsurePreloadCSP(nsIDocument* aDocument,
+BasePrincipal::EnsurePreloadCSP(dom::Document* aDocument,
                                 nsIContentSecurityPolicy** aPreloadCSP) {
   if (mPreloadCSP) {
     // if there is a speculative CSP already associated with this principal
     // then just return that - do not overwrite it!!!
     NS_IF_ADDREF(*aPreloadCSP = mPreloadCSP);
     return NS_OK;
   }
 

--- a/caps/BasePrincipal.h
+++ b/caps/BasePrincipal.h
@@ -16,16 +16,19 @@ class nsAtom;
 class nsIContentSecurityPolicy;
 class nsIObjectOutputStream;
 class nsIObjectInputStream;
 class nsIURI;
 
 class ExpandedPrincipal;
 
 namespace mozilla {
+namespace dom {
+class Document;
+}
 namespace extensions {
 class WebExtensionPolicy;
 }
 
 class BasePrincipal;
 
 // Codebase principals (and codebase principals embedded within expanded
 // principals) stored in SiteIdentifier are guaranteed to contain only the
@@ -100,20 +103,20 @@ class BasePrincipal : public nsJSPrincip
                                        bool* _retval) final;
   NS_IMETHOD SubsumesConsideringDomainIgnoringFPD(nsIPrincipal* other,
                                                   bool* _retval) final;
   NS_IMETHOD CheckMayLoad(nsIURI* uri, bool report,
                           bool allowIfInheritsPrincipal) final;
   NS_IMETHOD GetAddonPolicy(nsISupports** aResult) final;
   NS_IMETHOD GetCsp(nsIContentSecurityPolicy** aCsp) override;
   NS_IMETHOD SetCsp(nsIContentSecurityPolicy* aCsp) override;
-  NS_IMETHOD EnsureCSP(nsIDocument* aDocument,
+  NS_IMETHOD EnsureCSP(dom::Document* aDocument,
                        nsIContentSecurityPolicy** aCSP) override;
   NS_IMETHOD GetPreloadCsp(nsIContentSecurityPolicy** aPreloadCSP) override;
-  NS_IMETHOD EnsurePreloadCSP(nsIDocument* aDocument,
+  NS_IMETHOD EnsurePreloadCSP(dom::Document* aDocument,
                               nsIContentSecurityPolicy** aCSP) override;
   NS_IMETHOD GetCspJSON(nsAString& outCSPinJSON) override;
   NS_IMETHOD GetIsNullPrincipal(bool* aResult) override;
   NS_IMETHOD GetIsCodebasePrincipal(bool* aResult) override;
   NS_IMETHOD GetIsExpandedPrincipal(bool* aResult) override;
   NS_IMETHOD GetIsSystemPrincipal(bool* aResult) override;
   NS_IMETHOD GetIsAddonOrExpandedAddonPrincipal(bool* aResult) override;
   NS_IMETHOD GetOriginAttributes(JSContext* aCx,

--- a/caps/SystemPrincipal.cpp
+++ b/caps/SystemPrincipal.cpp
@@ -61,30 +61,30 @@ NS_IMETHODIMP
 SystemPrincipal::SetCsp(nsIContentSecurityPolicy* aCsp) {
   // Never destroy an existing CSP on the principal.
   // This method should only be called in rare cases.
 
   return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
-SystemPrincipal::EnsureCSP(nsIDocument* aDocument,
+SystemPrincipal::EnsureCSP(dom::Document* aDocument,
                            nsIContentSecurityPolicy** aCSP) {
   // CSP on a system principal makes no sense
   return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
 SystemPrincipal::GetPreloadCsp(nsIContentSecurityPolicy** aPreloadCSP) {
   *aPreloadCSP = nullptr;
   return NS_OK;
 }
 
 NS_IMETHODIMP
-SystemPrincipal::EnsurePreloadCSP(nsIDocument* aDocument,
+SystemPrincipal::EnsurePreloadCSP(dom::Document* aDocument,
                                   nsIContentSecurityPolicy** aPreloadCSP) {
   // CSP on a system principal makes no sense
   return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
 SystemPrincipal::GetDomain(nsIURI** aDomain) {
   *aDomain = nullptr;

--- a/caps/SystemPrincipal.h
+++ b/caps/SystemPrincipal.h
@@ -35,20 +35,20 @@ class SystemPrincipal final : public Bas
   NS_DECL_NSISERIALIZABLE
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
   uint32_t GetHashValue() override;
   NS_IMETHOD GetURI(nsIURI** aURI) override;
   NS_IMETHOD GetDomain(nsIURI** aDomain) override;
   NS_IMETHOD SetDomain(nsIURI* aDomain) override;
   NS_IMETHOD GetCsp(nsIContentSecurityPolicy** aCsp) override;
   NS_IMETHOD SetCsp(nsIContentSecurityPolicy* aCsp) override;
-  NS_IMETHOD EnsureCSP(nsIDocument* aDocument,
+  NS_IMETHOD EnsureCSP(dom::Document* aDocument,
                        nsIContentSecurityPolicy** aCSP) override;
   NS_IMETHOD GetPreloadCsp(nsIContentSecurityPolicy** aPreloadCSP) override;
-  NS_IMETHOD EnsurePreloadCSP(nsIDocument* aDocument,
+  NS_IMETHOD EnsurePreloadCSP(dom::Document* aDocument,
                               nsIContentSecurityPolicy** aCSP) override;
   NS_IMETHOD GetBaseDomain(nsACString& aBaseDomain) override;
   NS_IMETHOD GetAddonId(nsAString& aAddonId) override;
 
   virtual nsresult GetScriptLocation(nsACString& aStr) override;
 
   nsresult GetSiteIdentifier(SiteIdentifier& aSite) override {
     aSite.Init(this);

--- a/caps/nsScriptSecurityManager.cpp
+++ b/caps/nsScriptSecurityManager.cpp
@@ -385,17 +385,17 @@ nsresult nsScriptSecurityManager::GetCha
  * that may or may not inherit)."
  */
 NS_IMETHODIMP
 nsScriptSecurityManager::GetChannelURIPrincipal(nsIChannel* aChannel,
                                                 nsIPrincipal** aPrincipal) {
   MOZ_ASSERT(aChannel, "Must have channel!");
 
   // Get the principal from the URI.  Make sure this does the same thing
-  // as nsIDocument::Reset and XULDocument::StartDocumentLoad.
+  // as Document::Reset and XULDocument::StartDocumentLoad.
   nsCOMPtr<nsIURI> uri;
   nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
   NS_ENSURE_SUCCESS(rv, rv);
 
   nsCOMPtr<nsILoadInfo> loadInfo;
   aChannel->GetLoadInfo(getter_AddRefs(loadInfo));
 
   // Inherit the origin attributes from loadInfo.

--- a/chrome/nsChromeRegistry.cpp
+++ b/chrome/nsChromeRegistry.cpp
@@ -13,17 +13,17 @@
 #include "nsEscape.h"
 #include "nsNetUtil.h"
 #include "nsString.h"
 #include "nsQueryObject.h"
 
 #include "mozilla/dom/URL.h"
 #include "nsDOMWindowList.h"
 #include "nsIConsoleService.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIDOMWindow.h"
 #include "nsIObserverService.h"
 #include "nsIPresShell.h"
 #include "nsIScriptError.h"
 #include "nsIWindowMediator.h"
 #include "nsIPrefService.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Printf.h"
@@ -34,16 +34,17 @@
 
 #include "unicode/uloc.h"
 
 nsChromeRegistry* nsChromeRegistry::gChromeRegistry;
 
 // DO NOT use namespace mozilla; it'll break due to a naming conflict between
 // mozilla::TextRange and a TextRange in OSX headers.
 using mozilla::StyleSheet;
+using mozilla::dom::Document;
 using mozilla::dom::IsChromeURI;
 using mozilla::dom::Location;
 
 ////////////////////////////////////////////////////////////////////////////////
 
 void nsChromeRegistry::LogMessage(const char* aMsg, ...) {
   nsCOMPtr<nsIConsoleService> console(
       do_GetService(NS_CONSOLESERVICE_CONTRACTID));
@@ -270,17 +271,17 @@ nsChromeRegistry::ConvertChromeURL(nsIUR
 }
 
 ////////////////////////////////////////////////////////////////////////
 
 // theme stuff
 
 static void FlushSkinBindingsForWindow(nsPIDOMWindowOuter* aWindow) {
   // Get the document.
-  nsCOMPtr<nsIDocument> document = aWindow->GetDoc();
+  RefPtr<Document> document = aWindow->GetDoc();
   if (!document) return;
 
   // Annihilate all XBL bindings.
   document->FlushSkinBindings();
 }
 
 // XXXbsmedberg: move this to nsIWindowMediator
 NS_IMETHODIMP nsChromeRegistry::RefreshSkins() {
@@ -334,17 +335,17 @@ nsresult nsChromeRegistry::RefreshWindow
   uint32_t length = frames->GetLength();
   for (uint32_t j = 0; j < length; j++) {
     nsCOMPtr<nsPIDOMWindowOuter> piWindow = frames->IndexedGetter(j);
     RefreshWindow(piWindow);
   }
 
   nsresult rv;
   // Get the document.
-  nsCOMPtr<nsIDocument> document = aWindow->GetDoc();
+  RefPtr<Document> document = aWindow->GetDoc();
   if (!document) return NS_OK;
 
   // Deal with the agent sheets first.  Have to do all the style sets by hand.
   nsCOMPtr<nsIPresShell> shell = document->GetShell();
   if (shell) {
     // Reload only the chrome URL agent style sheets.
     nsTArray<RefPtr<StyleSheet>> agentSheets;
     rv = shell->GetAgentStyleSheets(agentSheets);

--- a/devtools/client/shared/widgets/Chart.js
+++ b/devtools/client/shared/widgets/Chart.js
@@ -69,17 +69,17 @@ function PieTableChart(node, pie, table)
   this.pie = pie;
   this.table = table;
   EventEmitter.decorate(this);
 }
 
 /**
  * Creates the DOM for a pie+table chart.
  *
- * @param nsIDocument document
+ * @param Document document
  *        The document responsible with creating the DOM.
  * @param object
  *        An object containing all or some of the following properties:
  *          - title: a string displayed as the table chart's (description)/local
  *          - diameter: the diameter of the pie chart, in pixels
  *          - data: an array of items used to display each slice in the pie
  *                  and each row in the table;
  *                  @see `createPieChart` and `createTableChart` for details.
@@ -156,17 +156,17 @@ function createPieTableChart(document,
   });
 
   return proxy;
 }
 
 /**
  * Creates the DOM for a pie chart based on the specified properties.
  *
- * @param nsIDocument document
+ * @param Document document
  *        The document responsible with creating the DOM.
  * @param object
  *        An object containing all or some of the following properties:
  *          - data: an array of items used to display each slice; all the items
  *                  should be objects containing a `size` and a `label` property.
  *                  e.g: [{
  *                    size: 1,
  *                    label: "foo"
@@ -288,17 +288,17 @@ function createPieChart(document, { data
   }
 
   return proxy;
 }
 
 /**
  * Creates the DOM for a table chart based on the specified properties.
  *
- * @param nsIDocument document
+ * @param Document document
  *        The document responsible with creating the DOM.
  * @param object
  *        An object containing all or some of the following properties:
  *          - title: a string displayed as the chart's (description)/local
  *          - data: an array of items used to display each row; all the items
  *                  should be objects representing columns, for which the
  *                  properties' values will be displayed in each cell of a row.
  *                  e.g: [{

--- a/devtools/docs/getting-started/README.md
+++ b/devtools/docs/getting-started/README.md
@@ -2,11 +2,11 @@
 
 1. Learn [where the code is](./where-is-the-code.md) and about the [architecture](./architecture-overview.md) of the tools.
 2. [Set up your machine](./build.md) to build the tools, then [configure a development profile](development-profiles.md).
 3. You can now experiment by changing things and rebuilding, look at the [files and directories overview](../files/README.md) or you could also [find something to work on](../bugs-issues.md).
 
 ## Additional documentation
 
 * [MDN Web Docs](http://developer.mozilla.org/) (also known as *MDN*) has a lot of information about XUL elements, HTML, JS, DOM, Web APIs, Gecko-specific APIs, and more.
-* [DXR](http://dxr.mozilla.org/mozilla-central/source/) is a source code search engine - search for symbols you want to learn about, eg. `nsIDocument`. [Searchfox](http://searchfox.org/mozilla-central/source) is an alternative.
+* [DXR](http://dxr.mozilla.org/mozilla-central/source/) is a source code search engine - search for symbols you want to learn about, eg. `Document`. [Searchfox](http://searchfox.org/mozilla-central/source) is an alternative.
 
 It is a good idea to [add smart keyword searches](https://support.mozilla.org/en-US/kb/how-search-from-address-bar) for DXR and MDN, so you can search faster.

--- a/docshell/base/nsDSURIContentListener.cpp
+++ b/docshell/base/nsDSURIContentListener.cpp
@@ -5,17 +5,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsDocShell.h"
 #include "nsDSURIContentListener.h"
 #include "nsIChannel.h"
 #include "nsServiceManagerUtils.h"
 #include "nsDocShellCID.h"
 #include "nsIWebNavigationInfo.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIDOMWindow.h"
 #include "nsIHttpChannel.h"
 #include "nsError.h"
 #include "nsContentSecurityManager.h"
 #include "nsDocShellLoadTypes.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIMultiPartChannel.h"
 

--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -77,17 +77,17 @@
 #include "nsIContent.h"
 #include "nsIContentInlines.h"
 #include "nsIContentSecurityPolicy.h"
 #include "nsIContentViewer.h"
 #include "nsIController.h"
 #include "nsICookieService.h"
 #include "nsIDocShellTreeItem.h"
 #include "nsIDocShellTreeOwner.h"
-#include "nsIDocument.h"
+#include "mozilla/dom/Document.h"
 #include "nsIDocumentLoaderFactory.h"
 #include "nsIDOMWindow.h"
 #include "nsIEditingSession.h"
 #include "nsIExternalProtocolService.h"
 #include "nsIFormPOSTActionChannel.h"
 #include "nsIFrame.h"
 #include "nsIGlobalObject.h"
 #include "nsIHttpChannel.h"
@@ -563,33 +563,33 @@ nsDocShell::GetInterface(const nsIID& aI
     *aSink = mContentListener;
   } else if ((aIID.Equals(NS_GET_IID(nsIScriptGlobalObject)) ||
               aIID.Equals(NS_GET_IID(nsIGlobalObject)) ||
               aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter)) ||
               aIID.Equals(NS_GET_IID(mozIDOMWindowProxy)) ||
               aIID.Equals(NS_GET_IID(nsIDOMWindow))) &&
              NS_SUCCEEDED(EnsureScriptEnvironment())) {
     return mScriptGlobal->QueryInterface(aIID, aSink);
-  } else if (aIID.Equals(NS_GET_IID(nsIDocument)) &&
+  } else if (aIID.Equals(NS_GET_IID(Document)) &&
              NS_SUCCEEDED(EnsureContentViewer())) {
-    nsCOMPtr<nsIDocument> doc = mContentViewer->GetDocument();
+    RefPtr<Document> doc = mContentViewer->GetDocument();
     doc.forget(aSink);
     return *aSink ? NS_OK : NS_NOINTERFACE;
   } else if (aIID.Equals(NS_GET_IID(nsIApplicationCacheContainer))) {
     *aSink = nullptr;
 
     // Return application cache associated with this docshell, if any
 
     nsCOMPtr<nsIContentViewer> contentViewer;
     GetContentViewer(getter_AddRefs(contentViewer));
     if (!contentViewer) {
       return NS_ERROR_NO_INTERFACE;
     }
 
-    nsCOMPtr<nsIDocument> doc = contentViewer->GetDocument();
+    RefPtr<Document> doc = contentViewer->GetDocument();
     NS_ASSERTION(doc, "Should have a document.");
     if (!doc) {
       return NS_ERROR_NO_INTERFACE;
     }
 
 #if defined(DEBUG)
     MOZ_LOG(
         gDocShellLog, LogLevel::Debug,
@@ -1025,21 +1025,21 @@ nsDOMNavigationTiming* nsDocShell::GetNa
   if (nsContentUtils::GetCurrentJSContext() &&
       nsContentUtils::IsCallerChrome()) {
     return true;
   }
 
   MOZ_ASSERT(aOriginTreeItem && aTargetTreeItem, "need two docshells");
 
   // Get origin document principal
-  nsCOMPtr<nsIDocument> originDocument = aOriginTreeItem->GetDocument();
+  RefPtr<Document> originDocument = aOriginTreeItem->GetDocument();
   NS_ENSURE_TRUE(originDocument, false);
 
   // Get target principal
-  nsCOMPtr<nsIDocument> targetDocument = aTargetTreeItem->GetDocument();
+  RefPtr<Document> targetDocument = aTargetTreeItem->GetDocument();
   NS_ENSURE_TRUE(targetDocument, false);
 
   bool equal;
   nsresult rv = originDocument->NodePrincipal()->Equals(
       targetDocument->NodePrincipal(), &equal);
   if (NS_SUCCEEDED(rv) && equal) {
     return true;
   }
@@ -1204,31 +1204,31 @@ bool nsDocShell::SetCurrentURI(nsIURI* a
 }
 
 NS_IMETHODIMP
 nsDocShell::GetCharset(nsACString& aCharset) {
   aCharset.Truncate();
 
   nsIPresShell* presShell = GetPresShell();
   NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);
-  nsIDocument* doc = presShell->GetDocument();
+  Document* doc = presShell->GetDocument();
   NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
   doc->GetDocumentCharacterSet()->Name(aCharset);
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GatherCharsetMenuTelemetry() {
   nsCOMPtr<nsIContentViewer> viewer;
   GetContentViewer(getter_AddRefs(viewer));
   if (!viewer) {
     return NS_OK;
   }
 
-  nsIDocument* doc = viewer->GetDocument();
+  Document* doc = viewer->GetDocument();
   if (!doc || doc->WillIgnoreCharsetOverride()) {
     return NS_OK;
   }
 
   Telemetry::ScalarSet(Telemetry::ScalarID::ENCODING_OVERRIDE_USED, true);
 
   bool isFileURL = false;
   nsIURI* url = doc->GetOriginalURI();
@@ -1341,97 +1341,97 @@ void nsDocShell::GetParentCharset(const 
                                   nsIPrincipal** aPrincipal) {
   aCharset = mParentCharset;
   *aCharsetSource = mParentCharsetSource;
   NS_IF_ADDREF(*aPrincipal = mParentCharsetPrincipal);
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasMixedActiveContentLoaded(bool* aHasMixedActiveContentLoaded) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasMixedActiveContentLoaded = doc && doc->GetHasMixedActiveContentLoaded();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasMixedActiveContentBlocked(
     bool* aHasMixedActiveContentBlocked) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasMixedActiveContentBlocked =
       doc && doc->GetHasMixedActiveContentBlocked();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasMixedDisplayContentLoaded(
     bool* aHasMixedDisplayContentLoaded) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasMixedDisplayContentLoaded =
       doc && doc->GetHasMixedDisplayContentLoaded();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasMixedDisplayContentBlocked(
     bool* aHasMixedDisplayContentBlocked) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasMixedDisplayContentBlocked =
       doc && doc->GetHasMixedDisplayContentBlocked();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasTrackingContentBlocked(bool* aHasTrackingContentBlocked) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasTrackingContentBlocked = doc && doc->GetHasTrackingContentBlocked();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasTrackingContentLoaded(bool* aHasTrackingContentLoaded) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasTrackingContentLoaded = doc && doc->GetHasTrackingContentLoaded();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasCookiesBlockedByPermission(
     bool* aHasCookiesBlockedByPermission) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasCookiesBlockedByPermission =
       doc && doc->GetHasCookiesBlockedByPermission();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasCookiesBlockedDueToTrackers(
     bool* aHasCookiesBlockedDueToTrackers) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasCookiesBlockedDueToTrackers = doc && doc->GetHasTrackingCookiesBlocked();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasAllCookiesBeenBlocked(bool* aHasAllCookiesBeenBlocked) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasAllCookiesBeenBlocked = doc && doc->GetHasAllCookiesBlocked();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasForeignCookiesBeenBlocked(
     bool* aHasForeignCookiesBeenBlocked) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasForeignCookiesBeenBlocked = doc && doc->GetHasForeignCookiesBlocked();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetHasCookiesLoaded(bool* aHasCookiesLoaded) {
-  nsCOMPtr<nsIDocument> doc(GetDocument());
+  RefPtr<Document> doc(GetDocument());
   *aHasCookiesLoaded = doc && doc->GetHasCookiesLoaded();
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetAllowPlugins(bool* aAllowPlugins) {
   NS_ENSURE_ARG_POINTER(aAllowPlugins);
 
@@ -1874,17 +1874,17 @@ void nsDocShell::SetOrientationLock(hal:
 
 NS_IMETHODIMP
 nsDocShell::GetMayEnableCharacterEncodingMenu(
     bool* aMayEnableCharacterEncodingMenu) {
   *aMayEnableCharacterEncodingMenu = false;
   if (!mContentViewer) {
     return NS_OK;
   }
-  nsIDocument* doc = mContentViewer->GetDocument();
+  Document* doc = mContentViewer->GetDocument();
   if (!doc) {
     return NS_OK;
   }
   if (doc->WillIgnoreCharsetOverride()) {
     return NS_OK;
   }
 
   *aMayEnableCharacterEncodingMenu = true;
@@ -2233,17 +2233,17 @@ nsIDOMStorageManager* nsDocShell::TopSes
 NS_IMETHODIMP
 nsDocShell::GetCurrentDocumentChannel(nsIChannel** aResult) {
   NS_IF_ADDREF(*aResult = GetCurrentDocChannel());
   return NS_OK;
 }
 
 nsIChannel* nsDocShell::GetCurrentDocChannel() {
   if (mContentViewer) {
-    nsIDocument* doc = mContentViewer->GetDocument();
+    Document* doc = mContentViewer->GetDocument();
     if (doc) {
       return doc->GetChannel();
     }
   }
   return nullptr;
 }
 
 NS_IMETHODIMP
@@ -2471,17 +2471,17 @@ void nsDocShell::MaybeCreateInitialClien
   }
 
   nsIPrincipal* principal =
       aPrincipal ? aPrincipal : GetInheritedPrincipal(false);
 
   // Sometimes there is no principal available when we are called from
   // CreateAboutBlankContentViewer.  For example, sometimes the principal
   // is only extracted from the load context after the document is created
-  // in nsIDocument::ResetToURI().  Ideally we would do something similar
+  // in Document::ResetToURI().  Ideally we would do something similar
   // here, but for now lets just avoid the issue by not preallocating the
   // client.
   if (!principal) {
     return;
   }
 
   nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
   if (!win) {
@@ -2526,17 +2526,17 @@ Maybe<ClientInfo> nsDocShell::GetInitial
   if (mInitialClientSource) {
     Maybe<ClientInfo> result;
     result.emplace(mInitialClientSource->Info());
     return result;
   }
 
   nsGlobalWindowInner* innerWindow =
       mScriptGlobal ? mScriptGlobal->GetCurrentInnerWindowInternal() : nullptr;
-  nsIDocument* doc = innerWindow ? innerWindow->GetExtantDoc() : nullptr;
+  Document* doc = innerWindow ? innerWindow->GetExtantDoc() : nullptr;
 
   if (!doc || !doc->IsInitialDocument()) {
     return Maybe<ClientInfo>();
   }
 
   return innerWindow->GetClientInfo();
 }
 
@@ -2850,30 +2850,30 @@ bool nsDocShell::CanAccessItem(nsIDocShe
 
   // When the first party isolation is on, the top-level docShell may not have
   // the firstPartyDomain in its originAttributes, but its document will have
   // it. So we get the firstPartyDomain from the nodePrincipal of the document
   // before we compare the originAttributes.
   if (OriginAttributes::IsFirstPartyEnabled()) {
     if (aAccessingItem->ItemType() == nsIDocShellTreeItem::typeContent &&
         (accessingDS == accessingRootDS || accessingDS->GetIsMozBrowser())) {
-      nsCOMPtr<nsIDocument> accessingDoc = aAccessingItem->GetDocument();
+      RefPtr<Document> accessingDoc = aAccessingItem->GetDocument();
 
       if (accessingDoc) {
         nsCOMPtr<nsIPrincipal> accessingPrincipal =
             accessingDoc->NodePrincipal();
 
         accessingOA.mFirstPartyDomain =
             accessingPrincipal->OriginAttributesRef().mFirstPartyDomain;
       }
     }
 
     if (aTargetItem->ItemType() == nsIDocShellTreeItem::typeContent &&
         (targetDS == targetRootDS || targetDS->GetIsMozBrowser())) {
-      nsCOMPtr<nsIDocument> targetDoc = aAccessingItem->GetDocument();
+      RefPtr<Document> targetDoc = aAccessingItem->GetDocument();
 
       if (targetDoc) {
         nsCOMPtr<nsIPrincipal> targetPrincipal = targetDoc->NodePrincipal();
 
         targetOA.mFirstPartyDomain =
             targetPrincipal->OriginAttributesRef().mFirstPartyDomain;
       }
     }
@@ -3085,17 +3085,17 @@ bool nsDocShell::IsSandboxedFrom(nsIDocS
   if (aTargetDocShell == this) {
     return false;
   }
 
   // Default the sandbox flags to our flags, so that if we can't retrieve the
   // active document, we will still enforce our own.
   uint32_t sandboxFlags = mSandboxFlags;
   if (mContentViewer) {
-    nsCOMPtr<nsIDocument> doc = mContentViewer->GetDocument();
+    RefPtr<Document> doc = mContentViewer->GetDocument();
     if (doc) {
       sandboxFlags = doc->GetSandboxFlags();
     }
   }
 
   // If no flags, we are not sandboxed at all.
   if (!sandboxFlags) {
     return false;
@@ -3322,17 +3322,17 @@ nsDocShell::AddChild(nsIDocShellTreeItem
   if (mItemType == nsIDocShellTreeItem::typeChrome) {
     return NS_OK;
   }
 
   // get the parent's current charset
   if (!mContentViewer) {
     return NS_OK;
   }
-  nsIDocument* doc = mContentViewer->GetDocument();
+  Document* doc = mContentViewer->GetDocument();
   if (!doc) {
     return NS_OK;
   }
 
   bool isWyciwyg = false;
 
   if (mCurrentURI) {
     // Check if the url is wyciwyg
@@ -3662,17 +3662,17 @@ nsDocShell::GetCurrentSHEntry(nsISHEntry
   return NS_OK;
 }
 
 nsIScriptGlobalObject* nsDocShell::GetScriptGlobalObject() {
   NS_ENSURE_SUCCESS(EnsureScriptEnvironment(), nullptr);
   return mScriptGlobal;
 }
 
-nsIDocument* nsDocShell::GetDocument() {
+Document* nsDocShell::GetDocument() {
   NS_ENSURE_SUCCESS(EnsureContentViewer(), nullptr);
   return mContentViewer->GetDocument();
 }
 
 nsPIDOMWindowOuter* nsDocShell::GetWindow() {
   if (NS_FAILED(EnsureScriptEnvironment())) {
     return nullptr;
   }
@@ -3707,17 +3707,17 @@ NS_IMETHODIMP
 nsDocShell::GetContentBlockingLog(Promise** aPromise) {
   NS_ENSURE_ARG_POINTER(aPromise);
 
   if (!mContentViewer) {
     *aPromise = nullptr;
     return NS_ERROR_FAILURE;
   }
 
-  nsIDocument* doc = mContentViewer->GetDocument();
+  Document* doc = mContentViewer->GetDocument();
   ErrorResult rv;
   RefPtr<Promise> promise = Promise::Create(doc->GetOwnerGlobal(), rv);
   if (NS_WARN_IF(rv.Failed())) {
     return rv.StealNSResult();
   }
   promise->MaybeResolve(doc->GetContentBlockingLog()->Stringify());
   promise.forget(aPromise);
   return NS_OK;
@@ -4609,17 +4609,17 @@ nsDocShell::Reload(uint32_t aReloadFlags
 
   /* If you change this part of code, make sure bug 45297 does not re-occur */
   if (mOSHE) {
     rv = LoadHistoryEntry(mOSHE, loadType);
   } else if (mLSHE) {  // In case a reload happened before the current load is
                        // done
     rv = LoadHistoryEntry(mLSHE, loadType);
   } else {
-    nsCOMPtr<nsIDocument> doc(GetDocument());
+    RefPtr<Document> doc(GetDocument());
 
     if (!doc) {
       return NS_OK;
     }
 
     // Do not inherit owner from document
     uint32_t flags = INTERNAL_LOAD_FLAGS_NONE;
     nsAutoString srcdoc;
@@ -4735,21 +4735,21 @@ nsDocShell::Stop(uint32_t aStopFlags) {
       shellAsNav->Stop(aStopFlags);
     }
   }
 
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsDocShell::GetDocument(nsIDocument** aDocument) {
+nsDocShell::GetDocument(Document** aDocument) {
   NS_ENSURE_ARG_POINTER(aDocument);
   NS_ENSURE_SUCCESS(EnsureContentViewer(), NS_ERROR_FAILURE);
 
-  nsCOMPtr<nsIDocument> doc = mContentViewer->GetDocument();
+  RefPtr<Document> doc = mContentViewer->GetDocument();
   if (!doc) {
     return NS_ERROR_NOT_AVAILABLE;
   }
 
   doc.forget(aDocument);
   return NS_OK;
 }
 
@@ -5173,17 +5173,17 @@ nsDocShell::GetPositionAndSize(int32_t* 
     SetPositionAndSize(mBounds.X(), mBounds.Y(), r.Width(), r.Height(), 0);
   }
 
   // We should really consider just getting this information from
   // our window instead of duplicating the storage and code...
   if (aWidth || aHeight) {
     // Caller wants to know our size; make sure to give them up to
     // date information.
-    nsCOMPtr<nsIDocument> doc(do_GetInterface(GetAsSupports(mParent)));
+    RefPtr<Document> doc(do_GetInterface(GetAsSupports(mParent)));
     if (doc) {
       doc->FlushPendingNotifications(FlushType::Layout);
     }
   }
 
   DoGetPositionAndSize(aX, aY, aWidth, aHeight);
   return NS_OK;
 }
@@ -5366,17 +5366,17 @@ nsDocShell::SetIsActive(bool aIsActive) 
   nsCOMPtr<nsIPresShell> pshell = GetPresShell();
   if (pshell) {
     pshell->SetIsActive(aIsActive);
   }
 
   // Tell the window about it
   if (mScriptGlobal) {
     mScriptGlobal->SetIsBackground(!aIsActive);
-    if (nsCOMPtr<nsIDocument> doc = mScriptGlobal->GetExtantDoc()) {
+    if (RefPtr<Document> doc = mScriptGlobal->GetExtantDoc()) {
       // Update orientation when the top-level browsing context becomes active.
       if (aIsActive) {
         nsCOMPtr<nsIDocShellTreeItem> parent;
         GetSameTypeParent(getter_AddRefs(parent));
         if (!parent) {
           // We only care about the top-level browsing context.
           uint16_t orientation = OrientationLock();
           ScreenOrientation::UpdateActiveOrientationLock(orientation);
@@ -5385,17 +5385,17 @@ nsDocShell::SetIsActive(bool aIsActive) 
 
       doc->PostVisibilityUpdateEvent();
     }
   }
 
   // Tell the nsDOMNavigationTiming about it
   RefPtr<nsDOMNavigationTiming> timing = mTiming;
   if (!timing && mContentViewer) {
-    nsIDocument* doc = mContentViewer->GetDocument();
+    Document* doc = mContentViewer->GetDocument();
     if (doc) {
       timing = doc->GetNavigationTiming();
     }
   }
   if (timing) {
     timing->NotifyDocShellStateChanged(
         aIsActive ? nsDOMNavigationTiming::DocShellState::eActive
                   : nsDOMNavigationTiming::DocShellState::eInactive);
@@ -5533,17 +5533,17 @@ nsDocShell::SetMixedContentChannel(nsICh
 #endif
   mMixedContentChannel = aMixedContentChannel;
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetFailedChannel(nsIChannel** aFailedChannel) {
   NS_ENSURE_ARG_POINTER(aFailedChannel);
-  nsIDocument* doc = GetDocument();
+  Document* doc = GetDocument();
   if (!doc) {
     *aFailedChannel = nullptr;
     return NS_OK;
   }
   NS_IF_ADDREF(*aFailedChannel = doc->GetFailedChannel());
   return NS_OK;
 }
 
@@ -5566,17 +5566,17 @@ nsDocShell::GetAllowMixedContentAndConne
   GetSameTypeRootTreeItem(getter_AddRefs(sameTypeRoot));
   NS_ASSERTION(
       sameTypeRoot,
       "No document shell root tree item from document shell tree item!");
   *aIsRootDocShell =
       sameTypeRoot.get() == static_cast<nsIDocShellTreeItem*>(this);
 
   // now get the document from sameTypeRoot
-  nsCOMPtr<nsIDocument> rootDoc = sameTypeRoot->GetDocument();
+  RefPtr<Document> rootDoc = sameTypeRoot->GetDocument();
   if (rootDoc) {
     nsCOMPtr<nsIPrincipal> rootPrincipal = rootDoc->NodePrincipal();
 
     // For things with system principal (e.g. scratchpad) there is no uri
     // aRootHasSecureConnection should be false.
     nsCOMPtr<nsIURI> rootUri;
     if (nsContentUtils::IsSystemPrincipal(rootPrincipal) ||
         NS_FAILED(rootPrincipal->GetURI(getter_AddRefs(rootUri))) || !rootUri ||
@@ -5886,17 +5886,17 @@ nsDocShell::ForceRefreshURI(nsIURI* aURI
   loadState->SetResultPrincipalURI(aURI);
   loadState->SetResultPrincipalURIIsSome(true);
   loadState->SetKeepResultPrincipalURIIfSet(true);
 
   // Set the triggering pricipal to aPrincipal if available, or current
   // document's principal otherwise.
   nsCOMPtr<nsIPrincipal> principal = aPrincipal;
   if (!principal) {
-    nsCOMPtr<nsIDocument> doc = GetDocument();
+    RefPtr<Document> doc = GetDocument();
     if (!doc) {
       return NS_ERROR_FAILURE;
     }
     principal = doc->NodePrincipal();
   }
   loadState->SetTriggeringPrincipal(principal);
   loadState->SetPrincipalIsExplicit(true);
 
@@ -6799,17 +6799,17 @@ nsresult nsDocShell::EndPageLoad(nsIWebP
 
       // Parent window
       nsCOMPtr<nsIDocShellTreeItem> parentItem;
       GetSameTypeParent(getter_AddRefs(parentItem));
       if (!parentItem) {
         return NS_OK;
       }
 
-      nsCOMPtr<nsIDocument> parentDoc;
+      RefPtr<Document> parentDoc;
       parentDoc = parentItem->GetDocument();
       if (!parentDoc) {
         return NS_OK;
       }
 
       parentDoc->AddBlockedTrackingNode(frameElement);
 
       return NS_OK;
@@ -7046,17 +7046,17 @@ nsresult nsDocShell::EnsureContentViewer
     }
   }
 
   nsresult rv = CreateAboutBlankContentViewer(principal, baseURI);
 
   NS_ENSURE_STATE(mContentViewer);
 
   if (NS_SUCCEEDED(rv)) {
-    nsCOMPtr<nsIDocument> doc(GetDocument());
+    RefPtr<Document> doc(GetDocument());
     NS_ASSERTION(doc,
                  "Should have doc if CreateAboutBlankContentViewer "
                  "succeeded!");
 
     doc->SetIsInitialDocument(true);
 
     // Documents created using EnsureContentViewer may be transient
     // placeholders created by framescripts before content has a chance to
@@ -7069,17 +7069,17 @@ nsresult nsDocShell::EnsureContentViewer
   }
 
   return rv;
 }
 
 nsresult nsDocShell::CreateAboutBlankContentViewer(
     nsIPrincipal* aPrincipal, nsIURI* aBaseURI, bool aTryToSaveOldPresentation,
     bool aCheckPermitUnload) {
-  nsCOMPtr<nsIDocument> blankDoc;
+  RefPtr<Document> blankDoc;
   nsCOMPtr<nsIContentViewer> viewer;
   nsresult rv = NS_ERROR_FAILURE;
 
   /* mCreatingDocument should never be true at this point. However, it's
      a theoretical possibility. We want to know about it and make it stop,
      and this sounds like a job for an assertion. */
   NS_ASSERTION(!mCreatingDocument,
                "infinite(?) loop creating document averted");
@@ -7217,17 +7217,17 @@ nsresult nsDocShell::CreateAboutBlankCon
 
 NS_IMETHODIMP
 nsDocShell::CreateAboutBlankContentViewer(nsIPrincipal* aPrincipal) {
   return CreateAboutBlankContentViewer(aPrincipal, nullptr);
 }
 
 bool nsDocShell::CanSavePresentation(uint32_t aLoadType,
                                      nsIRequest* aNewRequest,
-                                     nsIDocument* aNewDocument) {
+                                     Document* aNewDocument) {
   if (!mOSHE) {
     return false;  // no entry to save into
   }
 
   nsCOMPtr<nsIContentViewer> viewer = mOSHE->GetContentViewer();
   if (viewer) {
     NS_WARNING("mOSHE already has a content viewer!");
     return false;
@@ -7267,17 +7267,17 @@ bool nsDocShell::CanSavePresentation(uin
   // Don't cache the content viewer if we're in a subframe.
   nsCOMPtr<nsIDocShellTreeItem> root;
   GetSameTypeParent(getter_AddRefs(root));
   if (root && root != this) {
     return false;  // this is a subframe load
   }
 
   // If the document does not want its presentation cached, then don't.
-  nsCOMPtr<nsIDocument> doc = mScriptGlobal->GetExtantDoc();
+  RefPtr<Document> doc = mScriptGlobal->GetExtantDoc();
   return doc && doc->CanSavePresentation(aNewRequest);
 }
 
 void nsDocShell::ReattachEditorToWindow(nsISHEntry* aSHEntry) {
   MOZ_ASSERT(!mIsBeingDestroyed);
 
   NS_ASSERTION(!mEditorData,
                "Why reattach an editor when we already have one?");
@@ -7402,17 +7402,17 @@ nsDocShell::BeginRestore(nsIContentViewe
     aContentViewer = mContentViewer;
   }
 
   // Dispatch events for restoring the presentation.  We try to simulate
   // the progress notifications loading the document would cause, so we add
   // the document's channel to the loadgroup to initiate stateChange
   // notifications.
 
-  nsCOMPtr<nsIDocument> doc = aContentViewer->GetDocument();
+  RefPtr<Document> doc = aContentViewer->GetDocument();
   if (doc) {
     nsIChannel* channel = doc->GetChannel();
     if (channel) {
       mEODForCurrentDocument = false;
       mIsRestoringDocument = true;
       mLoadGroup->AddRequest(channel, nullptr);
       mIsRestoringDocument = false;
     }
@@ -7460,17 +7460,17 @@ nsDocShell::FinishRestore() {
       child->FinishRestore();
     }
   }
 
   if (mOSHE && mOSHE->HasDetachedEditor()) {
     ReattachEditorToWindow(mOSHE);
   }
 
-  nsCOMPtr<nsIDocument> doc = GetDocument();
+  RefPtr<Document> doc = GetDocument();
   if (doc) {
     // Finally, we remove the request from the loadgroup.  This will
     // cause onStateChange(STATE_STOP) to fire, which will fire the
     // pageshow event to the chrome.
 
     nsIChannel* channel = doc->GetChannel();
     if (channel) {
       mIsRestoringDocument = true;
@@ -7605,17 +7605,17 @@ nsresult nsDocShell::RestoreFromHistory(
     return NS_ERROR_FAILURE;
   }
 
   if (mSavingOldViewer) {
     // We determined that it was safe to cache the document presentation
     // at the time we initiated the new load.  We need to check whether
     // it's still safe to do so, since there may have been DOM mutations
     // or new requests initiated.
-    nsCOMPtr<nsIDocument> doc = viewer->GetDocument();
+    RefPtr<Document> doc = viewer->GetDocument();
     nsIRequest* request = nullptr;
     if (doc) {
       request = doc->GetChannel();
     }
     mSavingOldViewer = CanSavePresentation(mLoadType, request, doc);
   }
 
   nsCOMPtr<nsIContentViewer> oldCv(mContentViewer);
@@ -7741,17 +7741,17 @@ nsresult nsDocShell::RestoreFromHistory(
         rootViewParent = oldRootView->GetParent();
 
         mContentViewer->GetBounds(newBounds);
       }
     }
   }
 
   nsCOMPtr<nsIContent> container;
-  nsCOMPtr<nsIDocument> sibling;
+  RefPtr<Document> sibling;
   if (rootViewParent && rootViewParent->GetParent()) {
     nsIFrame* frame = rootViewParent->GetParent()->GetFrame();
     container = frame ? frame->GetContent() : nullptr;
   }
   if (rootViewSibling) {
     nsIFrame* frame = rootViewSibling->GetFrame();
     sibling = frame ? frame->PresShell()->GetDocument() : nullptr;
   }
@@ -7782,17 +7782,17 @@ nsresult nsDocShell::RestoreFromHistory(
 
   // Grab all of the related presentation from the SHEntry now.
   // Clearing the viewer from the SHEntry will clear all of this state.
   nsCOMPtr<nsISupports> windowState = mLSHE->GetWindowState();
   mLSHE->SetWindowState(nullptr);
 
   bool sticky = mLSHE->GetSticky();
 
-  nsCOMPtr<nsIDocument> document = mContentViewer->GetDocument();
+  RefPtr<Document> document = mContentViewer->GetDocument();
 
   nsCOMArray<nsIDocShellTreeItem> childShells;
   int32_t i = 0;
   nsCOMPtr<nsIDocShellTreeItem> child;
   while (NS_SUCCEEDED(mLSHE->ChildShellAt(i++, getter_AddRefs(child))) &&
          child) {
     childShells.AppendObject(child);
   }
@@ -7863,17 +7863,17 @@ nsresult nsDocShell::RestoreFromHistory(
     newCv->SetFullZoom(pageZoom);
     newCv->SetOverrideDPPX(overrideDPPX);
     newCv->SetAuthorStyleDisabled(styleDisabled);
   }
 
   if (document) {
     RefPtr<nsDocShell> parent = GetParentDocshell();
     if (parent) {
-      nsCOMPtr<nsIDocument> d = parent->GetDocument();
+      RefPtr<Document> d = parent->GetDocument();
       if (d) {
         if (d->EventHandlingSuppressed()) {
           document->SuppressEventHandling(d->EventHandlingSuppressed());
         }
       }
     }
 
     // Use the uri from the mLSHE we had when we entered this function
@@ -8118,17 +8118,17 @@ nsresult nsDocShell::CreateContentViewer
   // wrong information :-(
   //
 
   if (mSavingOldViewer) {
     // We determined that it was safe to cache the document presentation
     // at the time we initiated the new load.  We need to check whether
     // it's still safe to do so, since there may have been DOM mutations
     // or new requests initiated.
-    nsCOMPtr<nsIDocument> doc = viewer->GetDocument();
+    RefPtr<Document> doc = viewer->GetDocument();
     mSavingOldViewer = CanSavePresentation(mLoadType, aRequest, doc);
   }
 
   NS_ASSERTION(!mLoadingURI, "Re-entering unload?");
 
   nsCOMPtr<nsIChannel> aOpenedChannel = do_QueryInterface(aRequest);
   if (aOpenedChannel) {
     aOpenedChannel->GetURI(getter_AddRefs(mLoadingURI));
@@ -8157,17 +8157,17 @@ nsresult nsDocShell::CreateContentViewer
     // We need to set the SH entry and our current URI here and not
     // at the moment we load the page. We want the same behavior
     // of Stop() as for a normal page load. See bug 514232 for details.
 
     // Revert mLoadType to load type to state the page load failed,
     // following function calls need it.
     mLoadType = mFailedLoadType;
 
-    nsIDocument* doc = viewer->GetDocument();
+    Document* doc = viewer->GetDocument();
     if (doc) {
       doc->SetFailedChannel(failedChannel);
     }
 
     nsCOMPtr<nsIPrincipal> triggeringPrincipal;
     if (failedChannel) {
       // Make sure we have a URI to set currentURI.
       NS_GetFinalChannelURI(failedChannel, getter_AddRefs(failedURI));
@@ -8263,17 +8263,17 @@ nsresult nsDocShell::CreateContentViewer
   mEODForCurrentDocument = false;
 
   // if this document is part of a multipart document,
   // the ID can be used to distinguish it from the other parts.
   nsCOMPtr<nsIMultiPartChannel> multiPartChannel(do_QueryInterface(aRequest));
   if (multiPartChannel) {
     nsCOMPtr<nsIPresShell> shell = GetPresShell();
     if (NS_SUCCEEDED(rv) && shell) {
-      nsIDocument* doc = shell->GetDocument();
+      Document* doc = shell->GetDocument();
       if (doc) {
         uint32_t partID;
         multiPartChannel->GetPartID(&partID);
         doc->SetPartID(partID);
       }
     }
   }
 
@@ -8487,17 +8487,17 @@ nsresult nsDocShell::SetupNewViewer(nsIC
   // until we have enough of the new page to show.  Just return with the new
   // viewer still set to hidden.
 
   return NS_OK;
 }
 
 nsresult nsDocShell::SetDocCurrentStateObj(nsISHEntry* aShEntry) {
   NS_ENSURE_STATE(mContentViewer);
-  nsCOMPtr<nsIDocument> document = GetDocument();
+  RefPtr<Document> document = GetDocument();
   NS_ENSURE_TRUE(document, NS_ERROR_FAILURE);
 
   nsCOMPtr<nsIStructuredCloneContainer> scContainer;
   if (aShEntry) {
     scContainer = aShEntry->GetStateData();
 
     // If aShEntry is null, just set the document's state object to null.
   }
@@ -8799,17 +8799,17 @@ nsresult nsDocShell::InternalLoad(nsDocS
       if (NS_SUCCEEDED(rv) && shouldLoad == nsIContentPolicy::REJECT_TYPE) {
         return NS_ERROR_CONTENT_BLOCKED_SHOW_ALT;
       }
 
       return NS_ERROR_CONTENT_BLOCKED;
     }
   }
 
-  nsIDocument* doc = mContentViewer ? mContentViewer->GetDocument() : nullptr;
+  Document* doc = mContentViewer ? mContentViewer->GetDocument() : nullptr;
 
   const bool isDocumentAuxSandboxed =
       doc && (doc->GetSandboxFlags() & SANDBOXED_AUXILIARY_NAVIGATION);
 
   if (mLoadURIDelegate && aLoadState->LoadType() != LOAD_ERROR_PAGE &&
       (!targetDocShell || targetDocShell == static_cast<nsIDocShell*>(this))) {
     // Dispatch only load requests for the current or a new window to the
     // delegate, e.g., to allow for GeckoView apps to handle the load event
@@ -8932,17 +8932,17 @@ nsresult nsDocShell::InternalLoad(nsDocS
                                EmptyString(),         // Features
                                getter_AddRefs(newWin));
 
       // In some cases the Open call doesn't actually result in a new
       // window being opened.  We can detect these cases by examining the
       // document in |newWin|, if any.
       nsCOMPtr<nsPIDOMWindowOuter> piNewWin = newWin;
       if (piNewWin) {
-        nsCOMPtr<nsIDocument> newDoc = piNewWin->GetExtantDoc();
+        RefPtr<Document> newDoc = piNewWin->GetExtantDoc();
         if (!newDoc || newDoc->IsInitialDocument()) {
           isNewWindow = true;
           aLoadState->SetLoadFlag(INTERNAL_LOAD_FLAGS_FIRST_LOAD);
         }
       }
 
       nsCOMPtr<nsIWebNavigation> webNav = do_GetInterface(newWin);
       targetDocShell = do_QueryInterface(webNav);
@@ -9085,17 +9085,17 @@ nsresult nsDocShell::InternalLoad(nsDocS
       aLoadState->SourceDocShell()->IsSandboxedFrom(this)) {
     return NS_ERROR_DOM_INVALID_ACCESS_ERR;
   }
 
   // If this docshell is owned by a frameloader, make sure to cancel
   // possible frameloader initialization before loading a new page.
   nsCOMPtr<nsIDocShellTreeItem> parent = GetParentDocshell();
   if (parent) {
-    nsCOMPtr<nsIDocument> doc = parent->GetDocument();
+    RefPtr<Document> doc = parent->GetDocument();
     if (doc) {
       doc->TryCancelFrameLoaderInitialization(this);
     }
   }
 
   bool loadFromExternal = false;
 
   // Before going any further vet loads initiated by external programs.
@@ -9235,17 +9235,17 @@ nsresult nsDocShell::InternalLoad(nsDocS
 
       // we need to assign aLoadState->SHEntry() to mLSHE right here, so that on
       // History loads, SetCurrentURI() called from OnNewURI() will send proper
       // onLocationChange() notifications to the browser to update back/forward
       // buttons.
       SetHistoryEntry(&mLSHE, aLoadState->SHEntry());
 
       // Set the doc's URI according to the new history entry's URI.
-      nsCOMPtr<nsIDocument> doc = GetDocument();
+      RefPtr<Document> doc = GetDocument();
       NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
       doc->SetDocumentURI(aLoadState->URI());
 
       /* This is a anchor traversal with in the same page.
        * call OnNewURI() so that, this traversal will be
        * recorded in session and global history.
        */
       nsCOMPtr<nsIPrincipal> newURITriggeringPrincipal,
@@ -9616,17 +9616,17 @@ nsresult nsDocShell::InternalLoad(nsDocS
       return NS_OK;
     }
   }
 
   return rv;
 }
 
 nsIPrincipal* nsDocShell::GetInheritedPrincipal(bool aConsiderCurrentDocument) {
-  nsCOMPtr<nsIDocument> document;
+  RefPtr<Document> document;
   bool inheritedFromCurrent = false;
 
   if (aConsiderCurrentDocument && mContentViewer) {
     document = mContentViewer->GetDocument();
     inheritedFromCurrent = true;
   }
 
   if (!document) {
@@ -9815,17 +9815,17 @@ nsresult nsDocShell::DoURILoad(nsDocShel
   } else {
     loadingWindow = nullptr;
     loadingNode = mScriptGlobal->AsOuter()->GetFrameElementInternal();
     if (loadingNode) {
       // If we have a loading node, then use that as our loadingPrincipal.
       loadingPrincipal = loadingNode->NodePrincipal();
 #ifdef DEBUG
       // Get the docshell type for requestingElement.
-      nsCOMPtr<nsIDocument> requestingDoc = loadingNode->OwnerDoc();
+      RefPtr<Document> requestingDoc = loadingNode->OwnerDoc();
       nsCOMPtr<nsIDocShell> elementDocShell = requestingDoc->GetDocShell();
       // requestingElement docshell type = current docshell type.
       MOZ_ASSERT(
           mItemType == elementDocShell->ItemType(),
           "subframes should have the same docshell type as their parent");
 #endif
     } else {
       // If this isn't a top-level load and mScriptGlobal's frame element is
@@ -10553,17 +10553,17 @@ nsresult nsDocShell::ScrollToAnchor(bool
       free(str);
     }
 
     // Above will fail if the anchor name is not UTF-8.  Need to
     // convert from document charset to unicode.
     if (NS_FAILED(rv)) {
       // Get a document charset
       NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);
-      nsIDocument* doc = mContentViewer->GetDocument();
+      Document* doc = mContentViewer->GetDocument();
       NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
       nsAutoCString charset;
       doc->GetDocumentCharacterSet()->Name(charset);
 
       nsCOMPtr<nsITextToSubURI> textToSubURI =
           do_GetService(NS_ITEXTTOSUBURI_CONTRACTID, &rv);
       NS_ENSURE_SUCCESS(rv, rv);
 
@@ -10880,17 +10880,17 @@ bool nsDocShell::OnNewURI(nsIURI* aURI, 
 }
 
 bool nsDocShell::OnLoadingSite(nsIChannel* aChannel, bool aFireOnLocationChange,
                                bool aAddToGlobalHistory) {
   nsCOMPtr<nsIURI> uri;
   // If this a redirect, use the final url (uri)
   // else use the original url
   //
-  // Note that this should match what documents do (see nsIDocument::Reset).
+  // Note that this should match what documents do (see Document::Reset).
   NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
   NS_ENSURE_TRUE(uri, false);
 
   // Pass false for aCloneSHChildren, since we're loading a new page here.
   return OnNewURI(uri, aChannel, nullptr, nullptr, mLoadType,
                   aFireOnLocationChange, aAddToGlobalHistory, false);
 }
 
@@ -10951,38 +10951,38 @@ nsDocShell::AddState(JS::Handle<JS::Valu
 
   // pushState effectively becomes replaceState when we've started a network
   // load but haven't adopted its document yet.  This mirrors what we do with
   // changes to the hash at this stage of the game.
   if (JustStartedNetworkLoad()) {
     aReplace = true;
   }
 
-  nsCOMPtr<nsIDocument> document = GetDocument();
+  RefPtr<Document> document = GetDocument();
   NS_ENSURE_TRUE(document, NS_ERROR_FAILURE);
 
   // Step 1: Serialize aData using structured clone.
   nsCOMPtr<nsIStructuredCloneContainer> scContainer;
 
   // scContainer->Init might cause arbitrary JS to run, and this code might
   // navigate the page we're on, potentially to a different origin! (bug
   // 634834)  To protect against this, we abort if our principal changes due
   // to the InitFromJSVal() call.
   {
-    nsCOMPtr<nsIDocument> origDocument = GetDocument();
+    RefPtr<Document> origDocument = GetDocument();
     if (!origDocument) {
       return NS_ERROR_DOM_SECURITY_ERR;
     }
     nsCOMPtr<nsIPrincipal> origPrincipal = origDocument->NodePrincipal();
 
     scContainer = new nsStructuredCloneContainer();
     rv = scContainer->InitFromJSVal(aData, aCx);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    nsCOMPtr<nsIDocument> newDocument = GetDocument();
+    RefPtr<Document> newDocument = GetDocument();
     if (!newDocument) {
       return NS_ERROR_DOM_SECURITY_ERR;
     }
     nsCOMPtr<nsIPrincipal> newPrincipal = newDocument->NodePrincipal();
 
     bool principalsEqual = false;
     origPrincipal->Equals(newPrincipal, &principalsEqual);
     NS_ENSURE_TRUE(principalsEqual, NS_ERROR_DOM_SECURITY_ERR);
@@ -12207,17 +12207,17 @@ nsresult nsDocShell::SetBaseUrlForWyciwy
   nsresult rv = NS_ERROR_NOT_AVAILABLE;
 
   if (sURIFixup) {
     rv = sURIFixup->CreateExposableURI(mCurrentURI, getter_AddRefs(baseURI));
   }
 
   // Get the current document and set the base uri
   if (baseURI) {
-    nsIDocument* document = aContentViewer->GetDocument();
+    Document* document = aContentViewer->GetDocument();
     if (document) {
       document->SetBaseURI(baseURI);
     }
   }
   return rv;
 }
 
 //*****************************************************************************
@@ -12344,17 +12344,17 @@ bool nsDocShell::IsOKToLoadURI(nsIURI* a
     return true;
   }
 
   if (!mLoadingURI) {
     return false;
   }
 
   bool isPrivateWin = false;
-  nsIDocument* doc = GetDocument();
+  Document* doc = GetDocument();
   if (doc) {
     isPrivateWin =
         doc->NodePrincipal()->OriginAttributesRef().mPrivateBrowsingId > 0;
   }
 
   nsCOMPtr<nsIScriptSecurityManager> secMan =
       do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID);
   return secMan && NS_SUCCEEDED(secMan->CheckSameOriginURI(
@@ -12673,17 +12673,17 @@ nsDocShell::OnLinkClickSync(nsIContent* 
     }
   }
 
   // Get the owner document of the link that was clicked, this will be
   // the document that the link is in, or the last document that the
   // link was in. From that document, we'll get the URI to use as the
   // referer, since the current URI in this docshell may be a
   // new document that we're in the process of loading.
-  nsCOMPtr<nsIDocument> refererDoc = aContent->OwnerDoc();
+  RefPtr<Document> refererDoc = aContent->OwnerDoc();
   NS_ENSURE_TRUE(refererDoc, NS_ERROR_UNEXPECTED);
 
   // Now check that the refererDoc's inner window is the current inner
   // window for mScriptGlobal.  If it's not, then we don't want to
   // follow this link.
   nsPIDOMWindowInner* refererInner = refererDoc->GetInnerWindow();
   NS_ENSURE_TRUE(refererInner, NS_ERROR_UNEXPECTED);
   if (!mScriptGlobal ||
@@ -12812,17 +12812,17 @@ bool nsDocShell::ShouldBlockLoadingForBa
   return canGoForward;
 }
 
 bool nsDocShell::PluginsAllowedInCurrentDoc() {
   if (!mContentViewer) {
     return false;
   }
 
-  nsIDocument* doc = mContentViewer->GetDocument();
+  Document* doc = mContentViewer->GetDocument();
   if (!doc) {
     return false;
   }
 
   return doc->GetAllowPlugins();
 }
 
 //----------------------------------------------------------------------
@@ -13010,17 +13010,17 @@ bool nsDocShell::CanSetOriginAttributes(
   MOZ_ASSERT(mChildList.IsEmpty());
   if (!mChildList.IsEmpty()) {
     return false;
   }
 
   // TODO: Bug 1273058 - mContentViewer should be null when setting origin
   // attributes.
   if (mContentViewer) {
-    nsIDocument* doc = mContentViewer->GetDocument();
+    Document* doc = mContentViewer->GetDocument();
     if (doc) {
       nsIURI* uri = doc->GetDocumentURI();
       if (!uri) {
         return false;
       }
       nsCString uriSpec = uri->GetSpecOrDefault();
       MOZ_ASSERT(uriSpec.EqualsLiteral("about:blank"));
       if (!uriSpec.EqualsLiteral("about:blank")) {
@@ -13250,19 +13250,19 @@ bool nsDocShell::InFrameSwap() {
 
 UniquePtr<ClientSource> nsDocShell::TakeInitialClientSource() {
   return std::move(mInitialClientSource);
 }
 
 NS_IMETHODIMP
 nsDocShell::IssueWarning(uint32_t aWarning, bool aAsError) {
   if (mContentViewer) {
-    nsCOMPtr<nsIDocument> doc = mContentViewer->GetDocument();
+    RefPtr<Document> doc = mContentViewer->GetDocument();
     if (doc) {
-      doc->WarnOnceAbout(nsIDocument::DeprecatedOperations(aWarning), aAsError);
+      doc->WarnOnceAbout(Document::DeprecatedOperations(aWarning), aAsError);
     }
   }
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetEditingSession(nsIEditingSession** aEditSession) {
   if (!NS_SUCCEEDED(EnsureEditorData())) {