Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1901 insertions, 0 deletions

diff --git a/accessible/base/nsAccessibilityService.cpp b/accessible/base/nsAccessibilityService.cpp
new file mode 100644
index 0000000000..01a0a6a237
--- /dev/null
+++ b/accessible/base/nsAccessibilityService.cpp
@@ -0,0 +1,1901 @@
+/* -*- 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 "nsAccessibilityService.h"
+
+// NOTE: alphabetically ordered
+#include "AccAttributes.h"
+#include "ApplicationAccessibleWrap.h"
+#include "ARIAGridAccessible.h"
+#include "ARIAMap.h"
+#include "DocAccessible-inl.h"
+#include "DocAccessibleChild.h"
+#include "FocusManager.h"
+#include "HTMLCanvasAccessible.h"
+#include "HTMLElementAccessibles.h"
+#include "HTMLImageMapAccessible.h"
+#include "HTMLLinkAccessible.h"
+#include "HTMLListAccessible.h"
+#include "HTMLSelectAccessible.h"
+#include "HTMLTableAccessible.h"
+#include "HyperTextAccessibleWrap.h"
+#include "RootAccessible.h"
+#include "StyleInfo.h"
+#include "nsAccUtils.h"
+#include "nsArrayUtils.h"
+#include "nsAttrName.h"
+#include "nsDOMTokenList.h"
+#include "nsCRT.h"
+#include "nsEventShell.h"
+#include "nsGkAtoms.h"
+#include "nsIFrameInlines.h"
+#include "nsServiceManagerUtils.h"
+#include "nsTextFormatter.h"
+#include "OuterDocAccessible.h"
+#include "Role.h"
+#ifdef MOZ_ACCESSIBILITY_ATK
+#  include "RootAccessibleWrap.h"
+#endif
+#include "States.h"
+#include "Statistics.h"
+#include "TextLeafAccessible.h"
+#include "TreeWalker.h"
+#include "xpcAccessibleApplication.h"
+
+#ifdef XP_WIN
+#  include "mozilla/a11y/Compatibility.h"
+#  include "mozilla/StaticPtr.h"
+#endif
+
+#ifdef A11Y_LOG
+#  include "Logging.h"
+#endif
+
+#include "nsExceptionHandler.h"
+#include "nsImageFrame.h"
+#include "nsINamed.h"
+#include "nsIObserverService.h"
+#include "nsMenuPopupFrame.h"
+#include "nsLayoutUtils.h"
+#include "nsTreeBodyFrame.h"
+#include "nsTreeColumns.h"
+#include "nsTreeUtils.h"
+#include "mozilla/a11y/AccTypes.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/dom/DOMStringList.h"
+#include "mozilla/dom/EventTarget.h"
+#include "mozilla/dom/HTMLTableElement.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/ProfilerMarkers.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/Services.h"
+
+#include "XULAlertAccessible.h"
+#include "XULComboboxAccessible.h"
+#include "XULElementAccessibles.h"
+#include "XULFormControlAccessible.h"
+#include "XULListboxAccessible.h"
+#include "XULMenuAccessible.h"
+#include "XULTabAccessible.h"
+#include "XULTreeGridAccessible.h"
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+using namespace mozilla::dom;
+
+/**
+ * Accessibility service force enable/disable preference.
+ * Supported values:
+ *   Accessibility is force enabled (accessibility should always be enabled): -1
+ *   Accessibility is enabled (will be started upon a request, default value): 0
+ *   Accessibility is force disabled (never enable accessibility):             1
+ */
+#define PREF_ACCESSIBILITY_FORCE_DISABLED "accessibility.force_disabled"
+
+////////////////////////////////////////////////////////////////////////////////
+// Statics
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * If the element has an ARIA attribute that requires a specific Accessible
+ * class, create and return it. Otherwise, return null.
+ */
+static LocalAccessible* MaybeCreateSpecificARIAAccessible(
+    const nsRoleMapEntry* aRoleMapEntry, const LocalAccessible* aContext,
+    nsIContent* aContent, DocAccessible* aDocument) {
+  if (aRoleMapEntry && aRoleMapEntry->accTypes & eTableCell) {
+    if (aContent->IsAnyOfHTMLElements(nsGkAtoms::td, nsGkAtoms::th) &&
+        aContext->IsHTMLTableRow()) {
+      // Don't use ARIAGridCellAccessible for a valid td/th because
+      // HTMLTableCellAccessible can provide additional info; e.g. row/col span
+      // from the layout engine.
+      return nullptr;
+    }
+    // A cell must be in a row.
+    if (aContext->Role() != roles::ROW) {
+      return nullptr;
+    }
+    // That row must be in a table, though there may be an intervening rowgroup.
+    Accessible* parent = aContext->GetNonGenericParent();
+    if (!parent) {
+      return nullptr;
+    }
+    if (!parent->IsTable() && parent->Role() == roles::GROUPING) {
+      parent = parent->GetNonGenericParent();
+      if (!parent) {
+        return nullptr;
+      }
+    }
+    if (parent->IsTable()) {
+      return new ARIAGridCellAccessible(aContent, aDocument);
+    }
+  }
+  return nullptr;
+}
+
+/**
+ * Return true if the element has an attribute (ARIA, title, or relation) that
+ * requires the creation of an Accessible for the element.
+ */
+static bool AttributesMustBeAccessible(nsIContent* aContent,
+                                       DocAccessible* aDocument) {
+  if (aContent->IsElement()) {
+    uint32_t attrCount = aContent->AsElement()->GetAttrCount();
+    for (uint32_t attrIdx = 0; attrIdx < attrCount; attrIdx++) {
+      const nsAttrName* attr = aContent->AsElement()->GetAttrNameAt(attrIdx);
+      if (attr->NamespaceEquals(kNameSpaceID_None)) {
+        nsAtom* attrAtom = attr->Atom();
+        if (attrAtom == nsGkAtoms::title && aContent->IsHTMLElement()) {
+          // If the author provided a title on an element that would not
+          // be accessible normally, assume an intent and make it accessible.
+          return true;
+        }
+
+        nsDependentAtomString attrStr(attrAtom);
+        if (!StringBeginsWith(attrStr, u"aria-"_ns)) continue;  // not ARIA
+
+        // A global state or a property and in case of token defined.
+        uint8_t attrFlags = aria::AttrCharacteristicsFor(attrAtom);
+        if ((attrFlags & ATTR_GLOBAL) &&
+            (!(attrFlags & ATTR_VALTOKEN) ||
+             nsAccUtils::HasDefinedARIAToken(aContent, attrAtom))) {
+          return true;
+        }
+      }
+    }
+
+    // If the given ID is referred by relation attribute then create an
+    // Accessible for it.
+    nsAutoString id;
+    if (nsCoreUtils::GetID(aContent, id) && !id.IsEmpty()) {
+      return aDocument->IsDependentID(aContent->AsElement(), id);
+    }
+  }
+
+  return false;
+}
+
+/**
+ * Return true if the element must be a generic Accessible, even if it has been
+ * marked presentational with role="presentation", etc. MustBeAccessible causes
+ * an Accessible to be created as if it weren't marked presentational at all;
+ * e.g. <table role="presentation" tabindex="0"> will expose roles::TABLE and
+ * support TableAccessible. In contrast, this function causes a generic
+ * Accessible to be created; e.g. <table role="presentation" style="position:
+ * fixed;"> will expose roles::TEXT_CONTAINER and will not support
+ * TableAccessible. This is necessary in certain cases for the
+ * RemoteAccessible cache.
+ */
+static bool MustBeGenericAccessible(nsIContent* aContent,
+                                    DocAccessible* aDocument) {
+  if (aContent->IsInNativeAnonymousSubtree() || aContent->IsSVGElement()) {
+    // We should not force create accs for anonymous content.
+    // This is an issue for inputs, which have an intermediate
+    // container with relevant overflow styling between the input
+    // and its internal input content.
+    // We should also avoid this for SVG elements (ie. `<foreignobject>`s
+    // which have default overflow:hidden styling).
+    return false;
+  }
+  nsIFrame* frame = aContent->GetPrimaryFrame();
+  MOZ_ASSERT(frame);
+  nsAutoCString overflow;
+  frame->Style()->GetComputedPropertyValue(eCSSProperty_overflow, overflow);
+  // If the frame has been transformed, and the content has any children, we
+  // should create an Accessible so that we can account for the transform when
+  // calculating the Accessible's bounds using the parent process cache.
+  // Ditto for content which is position: fixed or sticky or has overflow
+  // styling (auto, scroll, hidden).
+  // However, don't do this for XUL widgets, as this breaks XUL a11y code
+  // expectations in some cases. XUL widgets are only used in the parent
+  // process and can't be cached anyway.
+  return !aContent->IsXULElement() &&
+         ((aContent->HasChildren() && frame->IsTransformed()) ||
+          frame->IsStickyPositioned() ||
+          (frame->StyleDisplay()->mPosition == StylePositionProperty::Fixed &&
+           nsLayoutUtils::IsReallyFixedPos(frame)) ||
+          overflow.Equals("auto"_ns) || overflow.Equals("scroll"_ns) ||
+          overflow.Equals("hidden"_ns));
+}
+
+/**
+ * Return true if the element must be accessible.
+ */
+static bool MustBeAccessible(nsIContent* aContent, DocAccessible* aDocument) {
+  nsIFrame* frame = aContent->GetPrimaryFrame();
+  MOZ_ASSERT(frame);
+  // This document might be invisible when it first loads. Therefore, we must
+  // check focusability irrespective of visibility here. Otherwise, we might not
+  // create Accessibles for some focusable elements; e.g. a span with only a
+  // tabindex. Elements that are invisible within this document are excluded
+  // earlier in CreateAccessible.
+  if (frame->IsFocusable(/* aWithMouse */ false,
+                         /* aCheckVisibility */ false)) {
+    return true;
+  }
+
+  return AttributesMustBeAccessible(aContent, aDocument);
+}
+
+bool nsAccessibilityService::ShouldCreateImgAccessible(
+    mozilla::dom::Element* aElement, DocAccessible* aDocument) {
+  // The element must have a layout frame for us to proceed. If there is no
+  // frame, the image is likely hidden.
+  nsIFrame* frame = aElement->GetPrimaryFrame();
+  if (!frame) {
+    return false;
+  }
+
+  // If the element is not an img, and also not an embedded image via embed or
+  // object, then we should not create an accessible.
+  if (!aElement->IsHTMLElement(nsGkAtoms::img) &&
+      ((!aElement->IsHTMLElement(nsGkAtoms::embed) &&
+        !aElement->IsHTMLElement(nsGkAtoms::object)) ||
+       frame->AccessibleType() != AccType::eImageType)) {
+    return false;
+  }
+
+  nsAutoString newAltText;
+  const bool hasAlt = aElement->GetAttr(nsGkAtoms::alt, newAltText);
+  if (!hasAlt || !newAltText.IsEmpty()) {
+    // If there is no alt attribute, we should create an accessible. The
+    // author may have missed the attribute, and the AT may want to provide a
+    // name. If there is alt text, we should create an accessible.
+    return true;
+  }
+
+  if (newAltText.IsEmpty() && (nsCoreUtils::HasClickListener(aElement) ||
+                               MustBeAccessible(aElement, aDocument))) {
+    // If there is empty alt text, but there is a click listener for this img,
+    // or if it otherwise must be an accessible (e.g., if it has an aria-label
+    // attribute), we should create an accessible.
+    return true;
+  }
+
+  // Otherwise, no alt text means we should not create an accessible.
+  return false;
+}
+
+/**
+ * Return true if the SVG element should be accessible
+ */
+static bool MustSVGElementBeAccessible(nsIContent* aContent,
+                                       DocAccessible* aDocument) {
+  // https://w3c.github.io/svg-aam/#include_elements
+  for (nsIContent* childElm = aContent->GetFirstChild(); childElm;
+       childElm = childElm->GetNextSibling()) {
+    if (childElm->IsAnyOfSVGElements(nsGkAtoms::title, nsGkAtoms::desc)) {
+      return true;
+    }
+  }
+  return MustBeAccessible(aContent, aDocument);
+}
+
+/**
+ * Used by XULMap.h to map both menupopup and popup elements
+ */
+LocalAccessible* CreateMenupopupAccessible(Element* aElement,
+                                           LocalAccessible* aContext) {
+#ifdef MOZ_ACCESSIBILITY_ATK
+  // ATK considers this node to be redundant when within menubars, and it makes
+  // menu navigation with assistive technologies more difficult
+  // XXX In the future we will should this for consistency across the
+  // nsIAccessible implementations on each platform for a consistent scripting
+  // environment, but then strip out redundant accessibles in the AccessibleWrap
+  // class for each platform.
+  nsIContent* parent = aElement->GetParent();
+  if (parent && parent->IsXULElement(nsGkAtoms::menu)) return nullptr;
+#endif
+
+  return new XULMenupopupAccessible(aElement, aContext->Document());
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// LocalAccessible constructors
+
+static LocalAccessible* New_HyperText(Element* aElement,
+                                      LocalAccessible* aContext) {
+  return new HyperTextAccessibleWrap(aElement, aContext->Document());
+}
+
+template <typename AccClass>
+static LocalAccessible* New_HTMLDtOrDd(Element* aElement,
+                                       LocalAccessible* aContext) {
+  nsIContent* parent = aContext->GetContent();
+  if (parent->IsHTMLElement(nsGkAtoms::div)) {
+    // It is conforming in HTML to use a div to group dt/dd elements.
+    parent = parent->GetParent();
+  }
+
+  if (parent && parent->IsHTMLElement(nsGkAtoms::dl)) {
+    return new AccClass(aElement, aContext->Document());
+  }
+
+  return nullptr;
+}
+
+/**
+ * Cached value of the PREF_ACCESSIBILITY_FORCE_DISABLED preference.
+ */
+static int32_t sPlatformDisabledState = 0;
+
+////////////////////////////////////////////////////////////////////////////////
+// Markup maps array.
+
+#define Attr(name, value) \
+  { nsGkAtoms::name, nsGkAtoms::value }
+
+#define AttrFromDOM(name, DOMAttrName) \
+  { nsGkAtoms::name, nullptr, nsGkAtoms::DOMAttrName }
+
+#define AttrFromDOMIf(name, DOMAttrName, DOMAttrValue) \
+  { nsGkAtoms::name, nullptr, nsGkAtoms::DOMAttrName, nsGkAtoms::DOMAttrValue }
+
+#define MARKUPMAP(atom, new_func, r, ...) \
+  {nsGkAtoms::atom, new_func, static_cast<a11y::role>(r), {__VA_ARGS__}},
+
+static const MarkupMapInfo sHTMLMarkupMapList[] = {
+#include "HTMLMarkupMap.h"
+};
+
+static const MarkupMapInfo sMathMLMarkupMapList[] = {
+#include "MathMLMarkupMap.h"
+};
+
+#undef MARKUPMAP
+
+#define XULMAP(atom, ...) {nsGkAtoms::atom, __VA_ARGS__},
+
+#define XULMAP_TYPE(atom, new_type)                                          \
+  XULMAP(                                                                    \
+      atom,                                                                  \
+      [](Element* aElement, LocalAccessible* aContext) -> LocalAccessible* { \
+        return new new_type(aElement, aContext->Document());                 \
+      })
+
+static const XULMarkupMapInfo sXULMarkupMapList[] = {
+#include "XULMap.h"
+};
+
+#undef XULMAP_TYPE
+#undef XULMAP
+
+#undef Attr
+#undef AttrFromDOM
+#undef AttrFromDOMIf
+
+////////////////////////////////////////////////////////////////////////////////
+// nsAccessibilityService
+////////////////////////////////////////////////////////////////////////////////
+
+nsAccessibilityService* nsAccessibilityService::gAccessibilityService = nullptr;
+ApplicationAccessible* nsAccessibilityService::gApplicationAccessible = nullptr;
+xpcAccessibleApplication* nsAccessibilityService::gXPCApplicationAccessible =
+    nullptr;
+uint32_t nsAccessibilityService::gConsumers = 0;
+
+nsAccessibilityService::nsAccessibilityService()
+    : DocManager(),
+      FocusManager(),
+      mHTMLMarkupMap(ArrayLength(sHTMLMarkupMapList)),
+      mMathMLMarkupMap(ArrayLength(sMathMLMarkupMapList)),
+      mXULMarkupMap(ArrayLength(sXULMarkupMapList)) {}
+
+nsAccessibilityService::~nsAccessibilityService() {
+  NS_ASSERTION(IsShutdown(), "Accessibility wasn't shutdown!");
+  gAccessibilityService = nullptr;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIListenerChangeListener
+
+NS_IMETHODIMP
+nsAccessibilityService::ListenersChanged(nsIArray* aEventChanges) {
+  uint32_t targetCount;
+  nsresult rv = aEventChanges->GetLength(&targetCount);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  for (uint32_t i = 0; i < targetCount; i++) {
+    nsCOMPtr<nsIEventListenerChange> change =
+        do_QueryElementAt(aEventChanges, i);
+
+    RefPtr<EventTarget> target;
+    change->GetTarget(getter_AddRefs(target));
+    nsIContent* content(nsIContent::FromEventTargetOrNull(target));
+    if (!content || !content->IsHTMLElement()) {
+      continue;
+    }
+
+    uint32_t changeCount;
+    change->GetCountOfEventListenerChangesAffectingAccessibility(&changeCount);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (changeCount) {
+      Document* ownerDoc = content->OwnerDoc();
+      DocAccessible* document = GetExistingDocAccessible(ownerDoc);
+
+      if (document) {
+        LocalAccessible* acc = document->GetAccessible(content);
+        if (!acc && (content == document->GetContent() ||
+                     content == document->DocumentNode()->GetRootElement())) {
+          acc = document;
+        }
+        if (!acc && nsCoreUtils::HasClickListener(content)) {
+          // Create an accessible for a inaccessible element having click event
+          // handler.
+          document->ContentInserted(content, content->GetNextSibling());
+        } else if (acc) {
+          if (acc->IsHTMLLink() && !acc->AsHTMLLink()->IsLinked()) {
+            // Notify of a LINKED state change if an HTML link gets a click
+            // listener but does not have an href attribute.
+            RefPtr<AccEvent> linkedChangeEvent =
+                new AccStateChangeEvent(acc, states::LINKED);
+            document->FireDelayedEvent(linkedChangeEvent);
+          }
+
+          // A click listener change might mean losing or gaining an action.
+          acc->SendCache(CacheDomain::Actions, CacheUpdateType::Update);
+        }
+      }
+    }
+  }
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsISupports
+
+NS_IMPL_ISUPPORTS_INHERITED(nsAccessibilityService, DocManager, nsIObserver,
+                            nsIListenerChangeListener,
+                            nsISelectionListener)  // from SelectionManager
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIObserver
+
+NS_IMETHODIMP
+nsAccessibilityService::Observe(nsISupports* aSubject, const char* aTopic,
+                                const char16_t* aData) {
+  if (!nsCRT::strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+    Shutdown();
+  }
+
+  return NS_OK;
+}
+
+void nsAccessibilityService::NotifyOfAnchorJumpTo(nsIContent* aTargetNode) {
+  Document* documentNode = aTargetNode->GetUncomposedDoc();
+  if (documentNode) {
+    DocAccessible* document = GetDocAccessible(documentNode);
+    if (document) document->SetAnchorJump(aTargetNode);
+  }
+}
+
+void nsAccessibilityService::FireAccessibleEvent(uint32_t aEvent,
+                                                 LocalAccessible* aTarget) {
+  nsEventShell::FireEvent(aEvent, aTarget);
+}
+
+void nsAccessibilityService::NotifyOfPossibleBoundsChange(
+    mozilla::PresShell* aPresShell, nsIContent* aContent) {
+  if (IPCAccessibilityActive()) {
+    DocAccessible* document = aPresShell->GetDocAccessible();
+    if (document) {
+      // DocAccessible::GetAccessible() won't return the document if a root
+      // element like body is passed.
+      LocalAccessible* accessible = aContent == document->GetContent()
+                                        ? document
+                                        : document->GetAccessible(aContent);
+      if (accessible) {
+        document->QueueCacheUpdate(accessible, CacheDomain::Bounds);
+      }
+    }
+  }
+}
+
+void nsAccessibilityService::NotifyOfComputedStyleChange(
+    mozilla::PresShell* aPresShell, nsIContent* aContent) {
+  DocAccessible* document = aPresShell->GetDocAccessible();
+  if (!document) {
+    return;
+  }
+
+  // DocAccessible::GetAccessible() won't return the document if a root
+  // element like body is passed.
+  LocalAccessible* accessible = aContent == document->GetContent()
+                                    ? document
+                                    : document->GetAccessible(aContent);
+  if (!accessible && aContent && aContent->HasChildren() &&
+      !aContent->IsInNativeAnonymousSubtree()) {
+    // If the content has children and its frame has a transform, create an
+    // Accessible so that we can account for the transform when calculating
+    // the Accessible's bounds using the parent process cache. Ditto for
+    // position: fixed/sticky and content with overflow styling (hidden, auto,
+    // scroll)
+    if (const nsIFrame* frame = aContent->GetPrimaryFrame()) {
+      const auto& disp = *frame->StyleDisplay();
+      if (disp.HasTransform(frame) ||
+          disp.mPosition == StylePositionProperty::Fixed ||
+          disp.mPosition == StylePositionProperty::Sticky ||
+          disp.IsScrollableOverflow()) {
+        document->ContentInserted(aContent, aContent->GetNextSibling());
+      }
+    }
+  } else if (accessible && IPCAccessibilityActive()) {
+    accessible->MaybeQueueCacheUpdateForStyleChanges();
+  }
+}
+
+void nsAccessibilityService::NotifyOfResolutionChange(
+    mozilla::PresShell* aPresShell, float aResolution) {
+  DocAccessible* document = aPresShell->GetDocAccessible();
+  if (document && document->IPCDoc()) {
+    AutoTArray<mozilla::a11y::CacheData, 1> data;
+    RefPtr<AccAttributes> fields = new AccAttributes();
+    fields->SetAttribute(nsGkAtoms::resolution, aResolution);
+    data.AppendElement(mozilla::a11y::CacheData(0, fields));
+    document->IPCDoc()->SendCache(CacheUpdateType::Update, data);
+  }
+}
+
+void nsAccessibilityService::NotifyOfDevPixelRatioChange(
+    mozilla::PresShell* aPresShell, int32_t aAppUnitsPerDevPixel) {
+  DocAccessible* document = aPresShell->GetDocAccessible();
+  if (document && document->IPCDoc()) {
+    AutoTArray<mozilla::a11y::CacheData, 1> data;
+    RefPtr<AccAttributes> fields = new AccAttributes();
+    fields->SetAttribute(nsGkAtoms::_moz_device_pixel_ratio,
+                         aAppUnitsPerDevPixel);
+    data.AppendElement(mozilla::a11y::CacheData(0, fields));
+    document->IPCDoc()->SendCache(CacheUpdateType::Update, data);
+  }
+}
+
+LocalAccessible* nsAccessibilityService::GetRootDocumentAccessible(
+    PresShell* aPresShell, bool aCanCreate) {
+  PresShell* presShell = aPresShell;
+  Document* documentNode = aPresShell->GetDocument();
+  if (documentNode) {
+    nsCOMPtr<nsIDocShellTreeItem> treeItem(documentNode->GetDocShell());
+    if (treeItem) {
+      nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
+      treeItem->GetInProcessRootTreeItem(getter_AddRefs(rootTreeItem));
+      if (treeItem != rootTreeItem) {
+        nsCOMPtr<nsIDocShell> docShell(do_QueryInterface(rootTreeItem));
+        presShell = docShell->GetPresShell();
+      }
+
+      return aCanCreate ? GetDocAccessible(presShell)
+                        : presShell->GetDocAccessible();
+    }
+  }
+  return nullptr;
+}
+
+void nsAccessibilityService::NotifyOfTabPanelVisibilityChange(
+    PresShell* aPresShell, Element* aPanel, bool aNowVisible) {
+  MOZ_ASSERT(aPanel->GetParent()->IsXULElement(nsGkAtoms::tabpanels));
+
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (!document) {
+    return;
+  }
+
+  if (LocalAccessible* acc = document->GetAccessible(aPanel)) {
+    RefPtr<AccEvent> event =
+        new AccStateChangeEvent(acc, states::OFFSCREEN, aNowVisible);
+    document->FireDelayedEvent(event);
+  }
+}
+
+void nsAccessibilityService::ContentRangeInserted(PresShell* aPresShell,
+                                                  nsIContent* aStartChild,
+                                                  nsIContent* aEndChild) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+#ifdef A11Y_LOG
+  if (logging::IsEnabled(logging::eTree)) {
+    logging::MsgBegin("TREE", "content inserted; doc: %p", document);
+    logging::Node("container", aStartChild->GetParentNode());
+    for (nsIContent* child = aStartChild; child != aEndChild;
+         child = child->GetNextSibling()) {
+      logging::Node("content", child);
+    }
+    logging::MsgEnd();
+    logging::Stack();
+  }
+#endif
+
+  if (document) {
+    document->ContentInserted(aStartChild, aEndChild);
+  }
+}
+
+void nsAccessibilityService::ScheduleAccessibilitySubtreeUpdate(
+    PresShell* aPresShell, nsIContent* aContent) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+#ifdef A11Y_LOG
+  if (logging::IsEnabled(logging::eTree)) {
+    logging::MsgBegin("TREE", "schedule update; doc: %p", document);
+    logging::Node("content node", aContent);
+    logging::MsgEnd();
+  }
+#endif
+
+  if (document) {
+    document->ScheduleTreeUpdate(aContent);
+  }
+}
+
+void nsAccessibilityService::ContentRemoved(PresShell* aPresShell,
+                                            nsIContent* aChildNode) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+#ifdef A11Y_LOG
+  if (logging::IsEnabled(logging::eTree)) {
+    logging::MsgBegin("TREE", "content removed; doc: %p", document);
+    logging::Node("container node", aChildNode->GetFlattenedTreeParent());
+    logging::Node("content node", aChildNode);
+    logging::MsgEnd();
+  }
+#endif
+
+  if (document) {
+    document->ContentRemoved(aChildNode);
+  }
+
+#ifdef A11Y_LOG
+  if (logging::IsEnabled(logging::eTree)) {
+    logging::MsgEnd();
+    logging::Stack();
+  }
+#endif
+}
+
+void nsAccessibilityService::TableLayoutGuessMaybeChanged(
+    PresShell* aPresShell, nsIContent* aContent) {
+  if (DocAccessible* document = GetDocAccessible(aPresShell)) {
+    if (LocalAccessible* acc = document->GetAccessible(aContent)) {
+      if (LocalAccessible* table = nsAccUtils::TableFor(acc)) {
+        document->QueueCacheUpdate(table, CacheDomain::Table);
+      }
+    }
+  }
+}
+
+void nsAccessibilityService::ComboboxOptionMaybeChanged(
+    PresShell* aPresShell, nsIContent* aMutatingNode) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (!document) {
+    return;
+  }
+
+  for (nsIContent* cur = aMutatingNode; cur; cur = cur->GetParent()) {
+    if (cur->IsHTMLElement(nsGkAtoms::option)) {
+      if (LocalAccessible* accessible = document->GetAccessible(cur)) {
+        document->FireDelayedEvent(nsIAccessibleEvent::EVENT_NAME_CHANGE,
+                                   accessible);
+        break;
+      }
+      if (cur->IsHTMLElement(nsGkAtoms::select)) {
+        break;
+      }
+    }
+  }
+}
+
+void nsAccessibilityService::UpdateText(PresShell* aPresShell,
+                                        nsIContent* aContent) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (document) document->UpdateText(aContent);
+}
+
+void nsAccessibilityService::TreeViewChanged(PresShell* aPresShell,
+                                             nsIContent* aContent,
+                                             nsITreeView* aView) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (document) {
+    LocalAccessible* accessible = document->GetAccessible(aContent);
+    if (accessible) {
+      XULTreeAccessible* treeAcc = accessible->AsXULTree();
+      if (treeAcc) treeAcc->TreeViewChanged(aView);
+    }
+  }
+}
+
+void nsAccessibilityService::RangeValueChanged(PresShell* aPresShell,
+                                               nsIContent* aContent) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (document) {
+    LocalAccessible* accessible = document->GetAccessible(aContent);
+    if (accessible) {
+      document->FireDelayedEvent(nsIAccessibleEvent::EVENT_VALUE_CHANGE,
+                                 accessible);
+    }
+  }
+}
+
+void nsAccessibilityService::UpdateImageMap(nsImageFrame* aImageFrame) {
+  PresShell* presShell = aImageFrame->PresShell();
+  DocAccessible* document = GetDocAccessible(presShell);
+  if (document) {
+    LocalAccessible* accessible =
+        document->GetAccessible(aImageFrame->GetContent());
+    if (accessible) {
+      HTMLImageMapAccessible* imageMap = accessible->AsImageMap();
+      if (imageMap) {
+        imageMap->UpdateChildAreas();
+        return;
+      }
+
+      // If image map was initialized after we created an accessible (that'll
+      // be an image accessible) then recreate it.
+      RecreateAccessible(presShell, aImageFrame->GetContent());
+    }
+  }
+}
+
+void nsAccessibilityService::UpdateLabelValue(PresShell* aPresShell,
+                                              nsIContent* aLabelElm,
+                                              const nsString& aNewValue) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (document) {
+    LocalAccessible* accessible = document->GetAccessible(aLabelElm);
+    if (accessible) {
+      XULLabelAccessible* xulLabel = accessible->AsXULLabel();
+      NS_ASSERTION(xulLabel,
+                   "UpdateLabelValue was called for wrong accessible!");
+      if (xulLabel) xulLabel->UpdateLabelValue(aNewValue);
+    }
+  }
+}
+
+void nsAccessibilityService::PresShellActivated(PresShell* aPresShell) {
+  DocAccessible* document = aPresShell->GetDocAccessible();
+  if (document) {
+    RootAccessible* rootDocument = document->RootAccessible();
+    NS_ASSERTION(rootDocument, "Entirely broken tree: no root document!");
+    if (rootDocument) rootDocument->DocumentActivated(document);
+  }
+}
+
+void nsAccessibilityService::RecreateAccessible(PresShell* aPresShell,
+                                                nsIContent* aContent) {
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (document) document->RecreateAccessible(aContent);
+}
+
+void nsAccessibilityService::GetStringRole(uint32_t aRole, nsAString& aString) {
+#define ROLE(geckoRole, stringRole, ariaRole, atkRole, macRole, macSubrole, \
+             msaaRole, ia2Role, androidClass, nameRule)                     \
+  case roles::geckoRole:                                                    \
+    aString.AssignLiteral(stringRole);                                      \
+    return;
+
+  switch (aRole) {
+#include "RoleMap.h"
+    default:
+      aString.AssignLiteral("unknown");
+      return;
+  }
+
+#undef ROLE
+}
+
+void nsAccessibilityService::GetStringStates(uint32_t aState,
+                                             uint32_t aExtraState,
+                                             nsISupports** aStringStates) {
+  RefPtr<DOMStringList> stringStates =
+      GetStringStates(nsAccUtils::To64State(aState, aExtraState));
+
+  // unknown state
+  if (!stringStates->Length()) {
+    stringStates->Add(u"unknown"_ns);
+  }
+
+  stringStates.forget(aStringStates);
+}
+
+already_AddRefed<DOMStringList> nsAccessibilityService::GetStringStates(
+    uint64_t aStates) const {
+  RefPtr<DOMStringList> stringStates = new DOMStringList();
+
+  if (aStates & states::UNAVAILABLE) {
+    stringStates->Add(u"unavailable"_ns);
+  }
+  if (aStates & states::SELECTED) {
+    stringStates->Add(u"selected"_ns);
+  }
+  if (aStates & states::FOCUSED) {
+    stringStates->Add(u"focused"_ns);
+  }
+  if (aStates & states::PRESSED) {
+    stringStates->Add(u"pressed"_ns);
+  }
+  if (aStates & states::CHECKED) {
+    stringStates->Add(u"checked"_ns);
+  }
+  if (aStates & states::MIXED) {
+    stringStates->Add(u"mixed"_ns);
+  }
+  if (aStates & states::READONLY) {
+    stringStates->Add(u"readonly"_ns);
+  }
+  if (aStates & states::HOTTRACKED) {
+    stringStates->Add(u"hottracked"_ns);
+  }
+  if (aStates & states::DEFAULT) {
+    stringStates->Add(u"default"_ns);
+  }
+  if (aStates & states::EXPANDED) {
+    stringStates->Add(u"expanded"_ns);
+  }
+  if (aStates & states::COLLAPSED) {
+    stringStates->Add(u"collapsed"_ns);
+  }
+  if (aStates & states::BUSY) {
+    stringStates->Add(u"busy"_ns);
+  }
+  if (aStates & states::FLOATING) {
+    stringStates->Add(u"floating"_ns);
+  }
+  if (aStates & states::ANIMATED) {
+    stringStates->Add(u"animated"_ns);
+  }
+  if (aStates & states::INVISIBLE) {
+    stringStates->Add(u"invisible"_ns);
+  }
+  if (aStates & states::OFFSCREEN) {
+    stringStates->Add(u"offscreen"_ns);
+  }
+  if (aStates & states::SIZEABLE) {
+    stringStates->Add(u"sizeable"_ns);
+  }
+  if (aStates & states::MOVEABLE) {
+    stringStates->Add(u"moveable"_ns);
+  }
+  if (aStates & states::SELFVOICING) {
+    stringStates->Add(u"selfvoicing"_ns);
+  }
+  if (aStates & states::FOCUSABLE) {
+    stringStates->Add(u"focusable"_ns);
+  }
+  if (aStates & states::SELECTABLE) {
+    stringStates->Add(u"selectable"_ns);
+  }
+  if (aStates & states::LINKED) {
+    stringStates->Add(u"linked"_ns);
+  }
+  if (aStates & states::TRAVERSED) {
+    stringStates->Add(u"traversed"_ns);
+  }
+  if (aStates & states::MULTISELECTABLE) {
+    stringStates->Add(u"multiselectable"_ns);
+  }
+  if (aStates & states::EXTSELECTABLE) {
+    stringStates->Add(u"extselectable"_ns);
+  }
+  if (aStates & states::PROTECTED) {
+    stringStates->Add(u"protected"_ns);
+  }
+  if (aStates & states::HASPOPUP) {
+    stringStates->Add(u"haspopup"_ns);
+  }
+  if (aStates & states::REQUIRED) {
+    stringStates->Add(u"required"_ns);
+  }
+  if (aStates & states::ALERT) {
+    stringStates->Add(u"alert"_ns);
+  }
+  if (aStates & states::INVALID) {
+    stringStates->Add(u"invalid"_ns);
+  }
+  if (aStates & states::CHECKABLE) {
+    stringStates->Add(u"checkable"_ns);
+  }
+  if (aStates & states::SUPPORTS_AUTOCOMPLETION) {
+    stringStates->Add(u"autocompletion"_ns);
+  }
+  if (aStates & states::DEFUNCT) {
+    stringStates->Add(u"defunct"_ns);
+  }
+  if (aStates & states::SELECTABLE_TEXT) {
+    stringStates->Add(u"selectable text"_ns);
+  }
+  if (aStates & states::EDITABLE) {
+    stringStates->Add(u"editable"_ns);
+  }
+  if (aStates & states::ACTIVE) {
+    stringStates->Add(u"active"_ns);
+  }
+  if (aStates & states::MODAL) {
+    stringStates->Add(u"modal"_ns);
+  }
+  if (aStates & states::MULTI_LINE) {
+    stringStates->Add(u"multi line"_ns);
+  }
+  if (aStates & states::HORIZONTAL) {
+    stringStates->Add(u"horizontal"_ns);
+  }
+  if (aStates & states::OPAQUE1) {
+    stringStates->Add(u"opaque"_ns);
+  }
+  if (aStates & states::SINGLE_LINE) {
+    stringStates->Add(u"single line"_ns);
+  }
+  if (aStates & states::TRANSIENT) {
+    stringStates->Add(u"transient"_ns);
+  }
+  if (aStates & states::VERTICAL) {
+    stringStates->Add(u"vertical"_ns);
+  }
+  if (aStates & states::STALE) {
+    stringStates->Add(u"stale"_ns);
+  }
+  if (aStates & states::ENABLED) {
+    stringStates->Add(u"enabled"_ns);
+  }
+  if (aStates & states::SENSITIVE) {
+    stringStates->Add(u"sensitive"_ns);
+  }
+  if (aStates & states::EXPANDABLE) {
+    stringStates->Add(u"expandable"_ns);
+  }
+  if (aStates & states::PINNED) {
+    stringStates->Add(u"pinned"_ns);
+  }
+  if (aStates & states::CURRENT) {
+    stringStates->Add(u"current"_ns);
+  }
+
+  return stringStates.forget();
+}
+
+void nsAccessibilityService::GetStringEventType(uint32_t aEventType,
+                                                nsAString& aString) {
+  NS_ASSERTION(
+      nsIAccessibleEvent::EVENT_LAST_ENTRY == ArrayLength(kEventTypeNames),
+      "nsIAccessibleEvent constants are out of sync to kEventTypeNames");
+
+  if (aEventType >= ArrayLength(kEventTypeNames)) {
+    aString.AssignLiteral("unknown");
+    return;
+  }
+
+  aString.AssignASCII(kEventTypeNames[aEventType]);
+}
+
+void nsAccessibilityService::GetStringEventType(uint32_t aEventType,
+                                                nsACString& aString) {
+  MOZ_ASSERT(
+      nsIAccessibleEvent::EVENT_LAST_ENTRY == ArrayLength(kEventTypeNames),
+      "nsIAccessibleEvent constants are out of sync to kEventTypeNames");
+
+  if (aEventType >= ArrayLength(kEventTypeNames)) {
+    aString.AssignLiteral("unknown");
+    return;
+  }
+
+  aString = nsDependentCString(kEventTypeNames[aEventType]);
+}
+
+void nsAccessibilityService::GetStringRelationType(uint32_t aRelationType,
+                                                   nsAString& aString) {
+  NS_ENSURE_TRUE_VOID(aRelationType <=
+                      static_cast<uint32_t>(RelationType::LAST));
+
+#define RELATIONTYPE(geckoType, geckoTypeName, atkType, msaaType, ia2Type) \
+  case RelationType::geckoType:                                            \
+    aString.AssignLiteral(geckoTypeName);                                  \
+    return;
+
+  RelationType relationType = static_cast<RelationType>(aRelationType);
+  switch (relationType) {
+#include "RelationTypeMap.h"
+    default:
+      aString.AssignLiteral("unknown");
+      return;
+  }
+
+#undef RELATIONTYPE
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsAccessibilityService public
+
+LocalAccessible* nsAccessibilityService::CreateAccessible(
+    nsINode* aNode, LocalAccessible* aContext, bool* aIsSubtreeHidden) {
+  MOZ_ASSERT(aContext, "No context provided");
+  MOZ_ASSERT(aNode, "No node to create an accessible for");
+  MOZ_ASSERT(gConsumers, "No creation after shutdown");
+
+  if (aIsSubtreeHidden) *aIsSubtreeHidden = false;
+
+  DocAccessible* document = aContext->Document();
+  MOZ_ASSERT(!document->GetAccessible(aNode),
+             "We already have an accessible for this node.");
+
+  if (aNode->IsDocument()) {
+    // If it's document node then ask accessible document loader for
+    // document accessible, otherwise return null.
+    return GetDocAccessible(aNode->AsDocument());
+  }
+
+  // We have a content node.
+  if (!aNode->GetComposedDoc()) {
+    NS_WARNING("Creating accessible for node with no document");
+    return nullptr;
+  }
+
+  if (aNode->OwnerDoc() != document->DocumentNode()) {
+    NS_ERROR("Creating accessible for wrong document");
+    return nullptr;
+  }
+
+  if (!aNode->IsContent()) return nullptr;
+
+  nsIContent* content = aNode->AsContent();
+  if (aria::HasDefinedARIAHidden(content)) {
+    if (aIsSubtreeHidden) {
+      *aIsSubtreeHidden = true;
+    }
+    return nullptr;
+  }
+
+  // Check frame and its visibility.
+  nsIFrame* frame = content->GetPrimaryFrame();
+  if (frame) {
+    // If invisible or inert, we don't create an accessible, but we don't mark
+    // it with aIsSubtreeHidden = true, since visibility: hidden frame allows
+    // visible elements in subtree, and inert elements allow non-inert
+    // elements.
+    if (!frame->StyleVisibility()->IsVisible() || frame->StyleUI()->IsInert()) {
+      return nullptr;
+    }
+  } else if (nsCoreUtils::CanCreateAccessibleWithoutFrame(content)) {
+    // display:contents element doesn't have a frame, but retains the
+    // semantics. All its children are unaffected.
+    const nsRoleMapEntry* roleMapEntry = aria::GetRoleMap(content->AsElement());
+    RefPtr<LocalAccessible> newAcc = MaybeCreateSpecificARIAAccessible(
+        roleMapEntry, aContext, content, document);
+    const MarkupMapInfo* markupMap = nullptr;
+    if (!newAcc) {
+      markupMap = GetMarkupMapInfoFor(content);
+      if (markupMap && markupMap->new_func) {
+        newAcc = markupMap->new_func(content->AsElement(), aContext);
+      }
+    }
+
+    // Check whether this element has an ARIA role or attribute that requires
+    // us to create an Accessible.
+    const bool hasNonPresentationalARIARole =
+        roleMapEntry && !roleMapEntry->Is(nsGkAtoms::presentation) &&
+        !roleMapEntry->Is(nsGkAtoms::none);
+    if (!newAcc && (hasNonPresentationalARIARole ||
+                    AttributesMustBeAccessible(content, document))) {
+      newAcc = new HyperTextAccessibleWrap(content, document);
+    }
+
+    // If there's still no Accessible but we do have an entry in the markup
+    // map for this non-presentational element, create a generic
+    // HyperTextAccessible.
+    if (!newAcc && markupMap &&
+        (!roleMapEntry || hasNonPresentationalARIARole)) {
+      newAcc = new HyperTextAccessibleWrap(content, document);
+    }
+
+    if (newAcc) {
+      document->BindToDocument(newAcc, roleMapEntry);
+    }
+    return newAcc;
+  } else {
+    if (aIsSubtreeHidden) {
+      *aIsSubtreeHidden = true;
+    }
+    return nullptr;
+  }
+
+  if (frame->IsHiddenByContentVisibilityOnAnyAncestor(
+          nsIFrame::IncludeContentVisibility::Hidden)) {
+    if (aIsSubtreeHidden) {
+      *aIsSubtreeHidden = true;
+    }
+    return nullptr;
+  }
+
+  if (nsMenuPopupFrame* popupFrame = do_QueryFrame(frame)) {
+    // Hidden tooltips and panels don't create accessibles in the whole subtree.
+    // Showing them gets handled by RootAccessible::ProcessDOMEvent.
+    if (content->IsAnyOfXULElements(nsGkAtoms::tooltip, nsGkAtoms::panel)) {
+      nsPopupState popupState = popupFrame->PopupState();
+      if (popupState == ePopupHiding || popupState == ePopupInvisible ||
+          popupState == ePopupClosed) {
+        if (aIsSubtreeHidden) {
+          *aIsSubtreeHidden = true;
+        }
+        return nullptr;
+      }
+    }
+  }
+
+  if (frame->GetContent() != content) {
+    // Not the main content for this frame. This happens because <area>
+    // elements return the image frame as their primary frame. The main content
+    // for the image frame is the image content. If the frame is not an image
+    // frame or the node is not an area element then null is returned.
+    // This setup will change when bug 135040 is fixed. Make sure we don't
+    // create area accessible here. Hopefully assertion below will handle that.
+
+#ifdef DEBUG
+    nsImageFrame* imageFrame = do_QueryFrame(frame);
+    NS_ASSERTION(imageFrame && content->IsHTMLElement(nsGkAtoms::area),
+                 "Unknown case of not main content for the frame!");
+#endif
+    return nullptr;
+  }
+
+#ifdef DEBUG
+  nsImageFrame* imageFrame = do_QueryFrame(frame);
+  NS_ASSERTION(!imageFrame || !content->IsHTMLElement(nsGkAtoms::area),
+               "Image map manages the area accessible creation!");
+#endif
+
+  // Attempt to create an accessible based on what we know.
+  RefPtr<LocalAccessible> newAcc;
+
+  // Create accessible for visible text frames.
+  if (content->IsText()) {
+    nsIFrame::RenderedText text = frame->GetRenderedText(
+        0, UINT32_MAX, nsIFrame::TextOffsetType::OffsetsInContentText,
+        nsIFrame::TrailingWhitespace::DontTrim);
+    // Ignore not rendered text nodes and whitespace text nodes between table
+    // cells.
+    if (text.mString.IsEmpty() ||
+        (aContext->IsTableRow() &&
+         nsCoreUtils::IsWhitespaceString(text.mString))) {
+      if (aIsSubtreeHidden) *aIsSubtreeHidden = true;
+
+      return nullptr;
+    }
+
+    newAcc = CreateAccessibleByFrameType(frame, content, aContext);
+    MOZ_ASSERT(newAcc, "Accessible not created for text node!");
+    document->BindToDocument(newAcc, nullptr);
+    newAcc->AsTextLeaf()->SetText(text.mString);
+    return newAcc;
+  }
+
+  if (content->IsHTMLElement(nsGkAtoms::map)) {
+    // Create hyper text accessible for HTML map if it is used to group links
+    // (see http://www.w3.org/TR/WCAG10-HTML-TECHS/#group-bypass). If the HTML
+    // map rect is empty then it is used for links grouping. Otherwise it should
+    // be used in conjunction with HTML image element and in this case we don't
+    // create any accessible for it and don't walk into it. The accessibles for
+    // HTML area (HTMLAreaAccessible) the map contains are attached as
+    // children of the appropriate accessible for HTML image
+    // (ImageAccessible).
+    if (nsLayoutUtils::GetAllInFlowRectsUnion(frame, frame->GetParent())
+            .IsEmpty()) {
+      if (aIsSubtreeHidden) *aIsSubtreeHidden = true;
+
+      return nullptr;
+    }
+
+    newAcc = new HyperTextAccessibleWrap(content, document);
+    document->BindToDocument(newAcc, aria::GetRoleMap(content->AsElement()));
+    return newAcc;
+  }
+
+  const nsRoleMapEntry* roleMapEntry = aria::GetRoleMap(content->AsElement());
+
+  if (roleMapEntry && (roleMapEntry->Is(nsGkAtoms::presentation) ||
+                       roleMapEntry->Is(nsGkAtoms::none))) {
+    if (MustBeAccessible(content, document)) {
+      // If the element is focusable, a global ARIA attribute is applied to it
+      // or it is referenced by an ARIA relationship, then treat
+      // role="presentation" on the element as if the role is not there.
+      roleMapEntry = nullptr;
+    } else if (MustBeGenericAccessible(content, document)) {
+      // Clear roleMapEntry so that we use the generic role specified below.
+      // Otherwise, we'd expose roles::NOTHING as specified for presentation in
+      // ARIAMap.
+      roleMapEntry = nullptr;
+      newAcc = new EnumRoleHyperTextAccessible<roles::TEXT_CONTAINER>(content,
+                                                                      document);
+    } else {
+      return nullptr;
+    }
+  }
+
+  if (!newAcc && content->IsHTMLElement()) {  // HTML accessibles
+    // We should always use OuterDocAccessible for OuterDocs, even if there's a
+    // specific ARIA class we would otherwise use.
+    if (frame->AccessibleType() != eOuterDocType) {
+      newAcc = MaybeCreateSpecificARIAAccessible(roleMapEntry, aContext,
+                                                 content, document);
+    }
+
+    if (!newAcc) {
+      // Prefer to use markup to decide if and what kind of accessible to
+      // create,
+      const MarkupMapInfo* markupMap =
+          mHTMLMarkupMap.Get(content->NodeInfo()->NameAtom());
+      if (markupMap && markupMap->new_func) {
+        newAcc = markupMap->new_func(content->AsElement(), aContext);
+      }
+
+      if (!newAcc) {  // try by frame accessible type.
+        newAcc = CreateAccessibleByFrameType(frame, content, aContext);
+      }
+    }
+
+    // If table has strong ARIA role then all table descendants shouldn't
+    // expose their native roles.
+    if (!roleMapEntry && newAcc && aContext->HasStrongARIARole()) {
+      if (frame->AccessibleType() == eHTMLTableRowType) {
+        const nsRoleMapEntry* contextRoleMap = aContext->ARIARoleMap();
+        if (!contextRoleMap->IsOfType(eTable)) {
+          roleMapEntry = &aria::gEmptyRoleMap;
+        }
+
+      } else if (frame->AccessibleType() == eHTMLTableCellType &&
+                 aContext->ARIARoleMap() == &aria::gEmptyRoleMap) {
+        roleMapEntry = &aria::gEmptyRoleMap;
+
+      } else if (content->IsAnyOfHTMLElements(nsGkAtoms::dt, nsGkAtoms::li,
+                                              nsGkAtoms::dd) ||
+                 frame->AccessibleType() == eHTMLLiType) {
+        const nsRoleMapEntry* contextRoleMap = aContext->ARIARoleMap();
+        if (!contextRoleMap->IsOfType(eList)) {
+          roleMapEntry = &aria::gEmptyRoleMap;
+        }
+      }
+    }
+  }
+
+  // XUL accessibles.
+  if (!newAcc && content->IsXULElement()) {
+    if (content->IsXULElement(nsGkAtoms::panel)) {
+      // We filter here instead of in the XUL map because
+      // if we filter there and return null, we still end up
+      // creating a generic accessible at the end of this function.
+      // Doing the filtering here ensures we never create accessibles
+      // for panels whose popups aren't visible.
+      nsMenuPopupFrame* popupFrame = do_QueryFrame(frame);
+      if (!popupFrame) {
+        return nullptr;
+      }
+
+      nsPopupState popupState = popupFrame->PopupState();
+      if (popupState == ePopupHiding || popupState == ePopupInvisible ||
+          popupState == ePopupClosed) {
+        return nullptr;
+      }
+    }
+
+    // Prefer to use XUL to decide if and what kind of accessible to create.
+    const XULMarkupMapInfo* xulMap =
+        mXULMarkupMap.Get(content->NodeInfo()->NameAtom());
+    if (xulMap && xulMap->new_func) {
+      newAcc = xulMap->new_func(content->AsElement(), aContext);
+    }
+
+    // Any XUL/flex box can be used as tabpanel, make sure we create a proper
+    // accessible for it.
+    if (!newAcc && aContext->IsXULTabpanels() &&
+        content->GetParent() == aContext->GetContent()) {
+      LayoutFrameType frameType = frame->Type();
+      // FIXME(emilio): Why only these frame types?
+      if (frameType == LayoutFrameType::FlexContainer ||
+          frameType == LayoutFrameType::Scroll) {
+        newAcc = new XULTabpanelAccessible(content, document);
+      }
+    }
+  }
+
+  if (!newAcc) {
+    if (content->IsSVGElement()) {
+      if (content->IsSVGGeometryElement() ||
+          content->IsSVGElement(nsGkAtoms::image)) {
+        // Shape elements: rect, circle, ellipse, line, path, polygon,
+        // and polyline. 'use' and 'text' graphic elements require
+        // special support.
+        if (MustSVGElementBeAccessible(content, document)) {
+          newAcc = new EnumRoleAccessible<roles::GRAPHIC>(content, document);
+        }
+      } else if (content->IsSVGElement(nsGkAtoms::text)) {
+        newAcc = new HyperTextAccessibleWrap(content->AsElement(), document);
+      } else if (content->IsSVGElement(nsGkAtoms::svg)) {
+        // An <svg> element could contain <foreignObject>, which contains HTML
+        // but does not normally create its own Accessible. This means that the
+        // <svg> Accessible could have TextLeafAccessible children, so it must
+        // be a HyperTextAccessible.
+        newAcc =
+            new EnumRoleHyperTextAccessible<roles::DIAGRAM>(content, document);
+      } else if (content->IsSVGElement(nsGkAtoms::g) &&
+                 MustSVGElementBeAccessible(content, document)) {
+        // <g> can also contain <foreignObject>.
+        newAcc =
+            new EnumRoleHyperTextAccessible<roles::GROUPING>(content, document);
+      } else if (content->IsSVGElement(nsGkAtoms::a)) {
+        newAcc = new HTMLLinkAccessible(content, document);
+      }
+
+    } else if (content->IsMathMLElement()) {
+      const MarkupMapInfo* markupMap =
+          mMathMLMarkupMap.Get(content->NodeInfo()->NameAtom());
+      if (markupMap && markupMap->new_func) {
+        newAcc = markupMap->new_func(content->AsElement(), aContext);
+      }
+
+      // Fall back to text when encountering Content MathML.
+      if (!newAcc && !content->IsAnyOfMathMLElements(
+                         nsGkAtoms::annotation_, nsGkAtoms::annotation_xml_,
+                         nsGkAtoms::mpadded_, nsGkAtoms::mphantom_,
+                         nsGkAtoms::maligngroup_, nsGkAtoms::malignmark_,
+                         nsGkAtoms::mspace_, nsGkAtoms::semantics_)) {
+        newAcc = new HyperTextAccessibleWrap(content, document);
+      }
+    } else if (content->IsGeneratedContentContainerForMarker()) {
+      if (aContext->IsHTMLListItem()) {
+        newAcc = new HTMLListBulletAccessible(content, document);
+      }
+      if (aIsSubtreeHidden) {
+        *aIsSubtreeHidden = true;
+      }
+    }
+  }
+
+  // If no accessible, see if we need to create a generic accessible because
+  // of some property that makes this object interesting
+  // We don't do this for <body>, <html>, <window>, <dialog> etc. which
+  // correspond to the doc accessible and will be created in any case
+  if (!newAcc && !content->IsHTMLElement(nsGkAtoms::body) &&
+      content->GetParent() &&
+      (roleMapEntry || MustBeAccessible(content, document) ||
+       (content->IsHTMLElement() && nsCoreUtils::HasClickListener(content)))) {
+    // This content is focusable or has an interesting dynamic content
+    // accessibility property. If it's interesting we need it in the
+    // accessibility hierarchy so that events or other accessibles can point to
+    // it, or so that it can hold a state, etc.
+    if (content->IsHTMLElement() || content->IsMathMLElement()) {
+      // Interesting HTML/MathML container which may have selectable text and/or
+      // embedded objects
+      newAcc = new HyperTextAccessibleWrap(content, document);
+    } else {  // XUL, SVG, etc.
+      // Interesting generic non-HTML container
+      newAcc = new AccessibleWrap(content, document);
+    }
+  } else if (!newAcc && MustBeGenericAccessible(content, document)) {
+    newAcc = new EnumRoleHyperTextAccessible<roles::TEXT_CONTAINER>(content,
+                                                                    document);
+  }
+
+  if (newAcc) {
+    document->BindToDocument(newAcc, roleMapEntry);
+  }
+  return newAcc;
+}
+
+#if defined(ANDROID)
+#  include "mozilla/Monitor.h"
+#  include "mozilla/Maybe.h"
+
+static Maybe<Monitor> sAndroidMonitor;
+
+mozilla::Monitor& nsAccessibilityService::GetAndroidMonitor() {
+  if (!sAndroidMonitor.isSome()) {
+    sAndroidMonitor.emplace("nsAccessibility::sAndroidMonitor");
+  }
+
+  return *sAndroidMonitor;
+}
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+// nsAccessibilityService private
+
+bool nsAccessibilityService::Init() {
+  AUTO_PROFILER_MARKER_TEXT("nsAccessibilityService::Init", A11Y, {}, ""_ns);
+  // DO NOT ADD CODE ABOVE HERE: THIS CODE IS MEASURING TIMINGS.
+
+  // Initialize accessible document manager.
+  if (!DocManager::Init()) return false;
+
+  // Add observers.
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+  if (!observerService) return false;
+
+  observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+
+#if defined(XP_WIN)
+  // This information needs to be initialized before the observer fires.
+  if (XRE_IsParentProcess()) {
+    Compatibility::Init();
+  }
+#endif  // defined(XP_WIN)
+
+  // Subscribe to EventListenerService.
+  nsCOMPtr<nsIEventListenerService> eventListenerService =
+      do_GetService("@mozilla.org/eventlistenerservice;1");
+  if (!eventListenerService) return false;
+
+  eventListenerService->AddListenerChangeListener(this);
+
+  for (uint32_t i = 0; i < ArrayLength(sHTMLMarkupMapList); i++) {
+    mHTMLMarkupMap.InsertOrUpdate(sHTMLMarkupMapList[i].tag,
+                                  &sHTMLMarkupMapList[i]);
+  }
+  for (const auto& info : sMathMLMarkupMapList) {
+    mMathMLMarkupMap.InsertOrUpdate(info.tag, &info);
+  }
+
+  for (uint32_t i = 0; i < ArrayLength(sXULMarkupMapList); i++) {
+    mXULMarkupMap.InsertOrUpdate(sXULMarkupMapList[i].tag,
+                                 &sXULMarkupMapList[i]);
+  }
+
+#ifdef A11Y_LOG
+  logging::CheckEnv();
+#endif
+
+  gAccessibilityService = this;
+  NS_ADDREF(gAccessibilityService);  // will release in Shutdown()
+
+  if (XRE_IsParentProcess()) {
+    gApplicationAccessible = new ApplicationAccessibleWrap();
+  } else {
+    gApplicationAccessible = new ApplicationAccessible();
+  }
+
+  NS_ADDREF(gApplicationAccessible);  // will release in Shutdown()
+  gApplicationAccessible->Init();
+
+  CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::Accessibility,
+                                     "Active"_ns);
+
+  // Now its safe to start platform accessibility.
+  if (XRE_IsParentProcess()) PlatformInit();
+
+  statistics::A11yInitialized();
+
+  static const char16_t kInitIndicator[] = {'1', 0};
+  observerService->NotifyObservers(nullptr, "a11y-init-or-shutdown",
+                                   kInitIndicator);
+
+  return true;
+}
+
+void nsAccessibilityService::Shutdown() {
+  // Application is going to be closed, shutdown accessibility and mark
+  // accessibility service as shutdown to prevent calls of its methods.
+  // Don't null accessibility service static member at this point to be safe
+  // if someone will try to operate with it.
+
+  MOZ_ASSERT(gConsumers, "Accessibility was shutdown already");
+  UnsetConsumers(eXPCOM | eMainProcess | ePlatformAPI);
+
+  // Remove observers.
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+  if (observerService) {
+    observerService->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
+  }
+
+  // Stop accessible document loader.
+  DocManager::Shutdown();
+
+  SelectionManager::Shutdown();
+
+  if (XRE_IsParentProcess()) PlatformShutdown();
+
+  gApplicationAccessible->Shutdown();
+  NS_RELEASE(gApplicationAccessible);
+  gApplicationAccessible = nullptr;
+
+  NS_IF_RELEASE(gXPCApplicationAccessible);
+  gXPCApplicationAccessible = nullptr;
+
+#if defined(ANDROID)
+  // Don't allow the service to shut down while an a11y request is being handled
+  // in the UI thread, as the request may depend on state from the service.
+  MonitorAutoLock mal(GetAndroidMonitor());
+#endif
+  NS_RELEASE(gAccessibilityService);
+  gAccessibilityService = nullptr;
+
+  if (observerService) {
+    static const char16_t kShutdownIndicator[] = {'0', 0};
+    observerService->NotifyObservers(nullptr, "a11y-init-or-shutdown",
+                                     kShutdownIndicator);
+  }
+}
+
+already_AddRefed<LocalAccessible>
+nsAccessibilityService::CreateAccessibleByFrameType(nsIFrame* aFrame,
+                                                    nsIContent* aContent,
+                                                    LocalAccessible* aContext) {
+  DocAccessible* document = aContext->Document();
+
+  RefPtr<LocalAccessible> newAcc;
+  switch (aFrame->AccessibleType()) {
+    case eNoType:
+      return nullptr;
+    case eHTMLBRType:
+      newAcc = new HTMLBRAccessible(aContent, document);
+      break;
+    case eHTMLButtonType:
+      newAcc = new HTMLButtonAccessible(aContent, document);
+      break;
+    case eHTMLCanvasType:
+      newAcc = new HTMLCanvasAccessible(aContent, document);
+      break;
+    case eHTMLCaptionType:
+      if (aContext->IsTable() &&
+          aContext->GetContent() == aContent->GetParent()) {
+        newAcc = new HTMLCaptionAccessible(aContent, document);
+      }
+      break;
+    case eHTMLCheckboxType:
+      newAcc = new CheckboxAccessible(aContent, document);
+      break;
+    case eHTMLComboboxType:
+      newAcc = new HTMLComboboxAccessible(aContent, document);
+      break;
+    case eHTMLFileInputType:
+      newAcc = new HTMLFileInputAccessible(aContent, document);
+      break;
+    case eHTMLGroupboxType:
+      newAcc = new HTMLGroupboxAccessible(aContent, document);
+      break;
+    case eHTMLHRType:
+      newAcc = new HTMLHRAccessible(aContent, document);
+      break;
+    case eHTMLImageMapType:
+      newAcc = new HTMLImageMapAccessible(aContent, document);
+      break;
+    case eHTMLLiType:
+      if (aContext->IsList() &&
+          aContext->GetContent() == aContent->GetParent()) {
+        newAcc = new HTMLLIAccessible(aContent, document);
+      } else {
+        // Otherwise create a generic text accessible to avoid text jamming.
+        newAcc = new HyperTextAccessibleWrap(aContent, document);
+      }
+      break;
+    case eHTMLSelectListType:
+      newAcc = new HTMLSelectListAccessible(aContent, document);
+      break;
+    case eHTMLMediaType:
+      newAcc = new EnumRoleAccessible<roles::GROUPING>(aContent, document);
+      break;
+    case eHTMLRadioButtonType:
+      newAcc = new HTMLRadioButtonAccessible(aContent, document);
+      break;
+    case eHTMLRangeType:
+      newAcc = new HTMLRangeAccessible(aContent, document);
+      break;
+    case eHTMLSpinnerType:
+      newAcc = new HTMLSpinnerAccessible(aContent, document);
+      break;
+    case eHTMLTableType:
+    case eHTMLTableCellType:
+      // We handle markup and ARIA tables elsewhere. If we reach here, this is
+      // a CSS table part. Just create a generic text container.
+      newAcc = new HyperTextAccessibleWrap(aContent, document);
+      break;
+    case eHTMLTableRowType:
+      // This is a CSS table row. Don't expose it at all.
+      break;
+    case eHTMLTextFieldType:
+      newAcc = new HTMLTextFieldAccessible(aContent, document);
+      break;
+    case eHyperTextType: {
+      if (aContext->IsTable() || aContext->IsTableRow()) {
+        // This is some generic hyperText, for example a block frame element
+        // inserted between a table and table row. Treat it as presentational.
+        return nullptr;
+      }
+
+      if (!aContent->IsAnyOfHTMLElements(nsGkAtoms::dt, nsGkAtoms::dd,
+                                         nsGkAtoms::div, nsGkAtoms::thead,
+                                         nsGkAtoms::tfoot, nsGkAtoms::tbody)) {
+        newAcc = new HyperTextAccessibleWrap(aContent, document);
+      }
+      break;
+    }
+    case eImageType:
+      if (aContent->IsElement() &&
+          ShouldCreateImgAccessible(aContent->AsElement(), document)) {
+        newAcc = new ImageAccessible(aContent, document);
+      }
+      break;
+    case eOuterDocType:
+      newAcc = new OuterDocAccessible(aContent, document);
+      break;
+    case eTextLeafType:
+      newAcc = new TextLeafAccessible(aContent, document);
+      break;
+    default:
+      MOZ_ASSERT(false);
+      break;
+  }
+
+  return newAcc.forget();
+}
+
+void nsAccessibilityService::MarkupAttributes(
+    Accessible* aAcc, AccAttributes* aAttributes) const {
+  const mozilla::a11y::MarkupMapInfo* markupMap = GetMarkupMapInfoFor(aAcc);
+  if (!markupMap) return;
+
+  dom::Element* el = aAcc->IsLocal() ? aAcc->AsLocal()->Elm() : nullptr;
+  for (uint32_t i = 0; i < ArrayLength(markupMap->attrs); i++) {
+    const MarkupAttrInfo* info = markupMap->attrs + i;
+    if (!info->name) break;
+
+    if (info->DOMAttrName) {
+      if (!el) {
+        // XXX Expose DOM attributes for cached RemoteAccessibles.
+        continue;
+      }
+      if (info->DOMAttrValue) {
+        if (el->AttrValueIs(kNameSpaceID_None, info->DOMAttrName,
+                            info->DOMAttrValue, eCaseMatters)) {
+          aAttributes->SetAttribute(info->name, info->DOMAttrValue);
+        }
+        continue;
+      }
+
+      nsString value;
+      el->GetAttr(info->DOMAttrName, value);
+
+      if (!value.IsEmpty()) {
+        aAttributes->SetAttribute(info->name, std::move(value));
+      }
+
+      continue;
+    }
+
+    aAttributes->SetAttribute(info->name, info->value);
+  }
+}
+
+LocalAccessible* nsAccessibilityService::AddNativeRootAccessible(
+    void* aAtkAccessible) {
+#ifdef MOZ_ACCESSIBILITY_ATK
+  ApplicationAccessible* applicationAcc = ApplicationAcc();
+  if (!applicationAcc) return nullptr;
+
+  GtkWindowAccessible* nativeWnd =
+      new GtkWindowAccessible(static_cast<AtkObject*>(aAtkAccessible));
+
+  if (applicationAcc->AppendChild(nativeWnd)) return nativeWnd;
+#endif
+
+  return nullptr;
+}
+
+void nsAccessibilityService::RemoveNativeRootAccessible(
+    LocalAccessible* aAccessible) {
+#ifdef MOZ_ACCESSIBILITY_ATK
+  ApplicationAccessible* applicationAcc = ApplicationAcc();
+
+  if (applicationAcc) applicationAcc->RemoveChild(aAccessible);
+#endif
+}
+
+bool nsAccessibilityService::HasAccessible(nsINode* aDOMNode) {
+  if (!aDOMNode) return false;
+
+  Document* document = aDOMNode->OwnerDoc();
+  if (!document) return false;
+
+  DocAccessible* docAcc = GetExistingDocAccessible(aDOMNode->OwnerDoc());
+  if (!docAcc) return false;
+
+  return docAcc->HasAccessible(aDOMNode);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsAccessibilityService private (DON'T put methods here)
+
+void nsAccessibilityService::SetConsumers(uint32_t aConsumers, bool aNotify) {
+  if (gConsumers & aConsumers) {
+    return;
+  }
+
+  gConsumers |= aConsumers;
+  if (aNotify) {
+    NotifyOfConsumersChange();
+  }
+}
+
+void nsAccessibilityService::UnsetConsumers(uint32_t aConsumers) {
+  if (!(gConsumers & aConsumers)) {
+    return;
+  }
+
+  gConsumers &= ~aConsumers;
+  NotifyOfConsumersChange();
+}
+
+void nsAccessibilityService::GetConsumers(nsAString& aString) {
+  const char16_t* kJSONFmt =
+      u"{ \"XPCOM\": %s, \"MainProcess\": %s, \"PlatformAPI\": %s }";
+  nsString json;
+  nsTextFormatter::ssprintf(json, kJSONFmt,
+                            gConsumers & eXPCOM ? "true" : "false",
+                            gConsumers & eMainProcess ? "true" : "false",
+                            gConsumers & ePlatformAPI ? "true" : "false");
+  aString.Assign(json);
+}
+
+void nsAccessibilityService::NotifyOfConsumersChange() {
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+
+  if (!observerService) {
+    return;
+  }
+
+  nsAutoString consumers;
+  GetConsumers(consumers);
+  observerService->NotifyObservers(nullptr, "a11y-consumers-changed",
+                                   consumers.get());
+}
+
+const mozilla::a11y::MarkupMapInfo* nsAccessibilityService::GetMarkupMapInfoFor(
+    Accessible* aAcc) const {
+  if (LocalAccessible* localAcc = aAcc->AsLocal()) {
+    return localAcc->HasOwnContent()
+               ? GetMarkupMapInfoFor(localAcc->GetContent())
+               : nullptr;
+  }
+  // XXX For now, we assume all RemoteAccessibles are HTML elements. This
+  // isn't strictly correct, but as far as current callers are concerned,
+  // this doesn't matter. If that changes in future, we could expose the
+  // element type via AccGenericType.
+  return mHTMLMarkupMap.Get(aAcc->TagName());
+}
+
+nsAccessibilityService* GetOrCreateAccService(uint32_t aNewConsumer) {
+  // Do not initialize accessibility if it is force disabled.
+  if (PlatformDisabledState() == ePlatformIsDisabled) {
+    return nullptr;
+  }
+
+  if (!nsAccessibilityService::gAccessibilityService) {
+    RefPtr<nsAccessibilityService> service = new nsAccessibilityService();
+    if (!service->Init()) {
+      service->Shutdown();
+      return nullptr;
+    }
+  }
+
+  MOZ_ASSERT(nsAccessibilityService::gAccessibilityService,
+             "LocalAccessible service is not initialized.");
+  nsAccessibilityService::gAccessibilityService->SetConsumers(aNewConsumer);
+  return nsAccessibilityService::gAccessibilityService;
+}
+
+void MaybeShutdownAccService(uint32_t aFormerConsumer) {
+  nsAccessibilityService* accService =
+      nsAccessibilityService::gAccessibilityService;
+
+  if (!accService || nsAccessibilityService::IsShutdown()) {
+    return;
+  }
+
+  // Still used by XPCOM
+  if (nsCoreUtils::AccEventObserversExist() ||
+      xpcAccessibilityService::IsInUse() || accService->HasXPCDocuments()) {
+    // In case the XPCOM flag was unset (possibly because of the shutdown
+    // timer in the xpcAccessibilityService) ensure it is still present. Note:
+    // this should be fixed when all the consumer logic is taken out as a
+    // separate class.
+    accService->SetConsumers(nsAccessibilityService::eXPCOM, false);
+
+    if (aFormerConsumer != nsAccessibilityService::eXPCOM) {
+      // Only unset non-XPCOM consumers.
+      accService->UnsetConsumers(aFormerConsumer);
+    }
+    return;
+  }
+
+  if (nsAccessibilityService::gConsumers & ~aFormerConsumer) {
+    accService->UnsetConsumers(aFormerConsumer);
+  } else {
+    accService
+        ->Shutdown();  // Will unset all nsAccessibilityService::gConsumers
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Services
+////////////////////////////////////////////////////////////////////////////////
+
+namespace mozilla {
+namespace a11y {
+
+FocusManager* FocusMgr() {
+  return nsAccessibilityService::gAccessibilityService;
+}
+
+SelectionManager* SelectionMgr() {
+  return nsAccessibilityService::gAccessibilityService;
+}
+
+ApplicationAccessible* ApplicationAcc() {
+  return nsAccessibilityService::gApplicationAccessible;
+}
+
+xpcAccessibleApplication* XPCApplicationAcc() {
+  if (!nsAccessibilityService::gXPCApplicationAccessible &&
+      nsAccessibilityService::gApplicationAccessible) {
+    nsAccessibilityService::gXPCApplicationAccessible =
+        new xpcAccessibleApplication(
+            nsAccessibilityService::gApplicationAccessible);
+    NS_ADDREF(nsAccessibilityService::gXPCApplicationAccessible);
+  }
+
+  return nsAccessibilityService::gXPCApplicationAccessible;
+}
+
+EPlatformDisabledState PlatformDisabledState() {
+  static bool platformDisabledStateCached = false;
+  if (platformDisabledStateCached) {
+    return static_cast<EPlatformDisabledState>(sPlatformDisabledState);
+  }
+
+  platformDisabledStateCached = true;
+  Preferences::RegisterCallback(PrefChanged, PREF_ACCESSIBILITY_FORCE_DISABLED);
+  return ReadPlatformDisabledState();
+}
+
+EPlatformDisabledState ReadPlatformDisabledState() {
+  sPlatformDisabledState =
+      Preferences::GetInt(PREF_ACCESSIBILITY_FORCE_DISABLED, 0);
+  if (sPlatformDisabledState < ePlatformIsForceEnabled) {
+    sPlatformDisabledState = ePlatformIsForceEnabled;
+  } else if (sPlatformDisabledState > ePlatformIsDisabled) {
+    sPlatformDisabledState = ePlatformIsDisabled;
+  }
+
+  return static_cast<EPlatformDisabledState>(sPlatformDisabledState);
+}
+
+void PrefChanged(const char* aPref, void* aClosure) {
+  if (ReadPlatformDisabledState() == ePlatformIsDisabled) {
+    // Force shut down accessibility.
+    nsAccessibilityService* accService =
+        nsAccessibilityService::gAccessibilityService;
+    if (accService && !nsAccessibilityService::IsShutdown()) {
+      accService->Shutdown();
+    }
+  }
+}
+
+}  // namespace a11y
+}  // namespace mozilla