Adding upstream version 127.0.upstream/127.0

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

49 files changed, 2576 insertions, 266 deletions

diff --git a/accessible/base/ARIAMap.cpp b/accessible/base/ARIAMap.cpp
index d53592acf0..a557405497 100644
--- a/accessible/base/ARIAMap.cpp
+++ b/accessible/base/ARIAMap.cpp
@@ -256,7 +256,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-acknowledgments
@@ -286,7 +286,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-backlink
@@ -296,7 +296,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eJumpAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     states::LINKED
   },
   { // doc-biblioentry
@@ -306,7 +306,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     states::READONLY
   },
   { // doc-bibliography
@@ -316,7 +316,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-biblioref
@@ -326,7 +326,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eJumpAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     states::LINKED
   },
   { // doc-chapter
@@ -336,7 +336,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-colophon
@@ -346,7 +346,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-conclusion
@@ -356,7 +356,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-cover
@@ -366,7 +366,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-credit
@@ -376,7 +376,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-credits
@@ -386,7 +386,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-dedication
@@ -396,7 +396,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-endnote
@@ -406,7 +406,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     states::READONLY
   },
   { // doc-endnotes
@@ -416,7 +416,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-epigraph
@@ -426,7 +426,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-epilogue
@@ -436,7 +436,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-errata
@@ -446,17 +446,17 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-example
     nsGkAtoms::docExample,
-    roles::SECTION,
+    roles::FIGURE,
     kUseMapRole,
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-footnote
@@ -466,7 +466,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-foreword
@@ -476,7 +476,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-glossary
@@ -486,7 +486,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-glossref
@@ -496,7 +496,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eJumpAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     states::LINKED
   },
   { // doc-index
@@ -506,7 +506,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-introduction
@@ -516,7 +516,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-noteref
@@ -526,7 +526,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eJumpAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     states::LINKED
   },
   { // doc-notice
@@ -536,7 +536,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-pagebreak
@@ -546,7 +546,27 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
+    kNoReqStates
+  },
+  { // doc-pagefooter
+    nsGkAtoms::docPagefooter,
+    roles::SECTION,
+    kUseMapRole,
+    eNoValue,
+    eNoAction,
+    eNoLiveAttr,
+    eDPub,
+    kNoReqStates
+  },
+  { // doc-pageheader
+    nsGkAtoms::docPageheader,
+    roles::SECTION,
+    kUseMapRole,
+    eNoValue,
+    eNoAction,
+    eNoLiveAttr,
+    eDPub,
     kNoReqStates
   },
   { // doc-pagelist
@@ -556,7 +576,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-part
@@ -566,7 +586,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-preface
@@ -576,7 +596,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-prologue
@@ -586,7 +606,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // doc-pullquote
@@ -596,7 +616,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-qna
@@ -606,7 +626,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-subtitle
@@ -616,7 +636,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-tip
@@ -626,7 +646,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eDPub,
     kNoReqStates
   },
   { // doc-toc
@@ -636,7 +656,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] = {
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eLandmark,
+    eDPub | eLandmark,
     kNoReqStates
   },
   { // document
@@ -1589,6 +1609,19 @@ bool aria::HasDefinedARIAHidden(nsIContent* aContent) {
                                      eCaseMatters);
 }
 
+const nsRoleMapEntry* aria::GetRoleMap(const nsStaticAtom* aAriaRole) {
+  const nsDependentAtomString role(aAriaRole);
+  auto comparator = [&role](const nsRoleMapEntry& aEntry) {
+    return Compare(role, aEntry.ARIARoleString());
+  };
+  size_t idx;
+  if (BinarySearchIf(sWAIRoleMaps, 0, ArrayLength(sWAIRoleMaps), comparator,
+                     &idx)) {
+    return GetRoleMapFromIndex(idx);
+  }
+  return nullptr;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // AttrIterator class
 
diff --git a/accessible/base/ARIAMap.h b/accessible/base/ARIAMap.h
index 58a96b7112..2fa3ac80d4 100644
--- a/accessible/base/ARIAMap.h
+++ b/accessible/base/ARIAMap.h
@@ -305,6 +305,11 @@ uint8_t AttrCharacteristicsFor(nsAtom* aAtom);
 bool HasDefinedARIAHidden(nsIContent* aContent);
 
 /**
+ * Get the role map entry for a given ARIA role.
+ */
+const nsRoleMapEntry* GetRoleMap(const nsStaticAtom* aAriaRole);
+
+/**
  * Represents a simple enumerator for iterating through ARIA attributes
  * exposed as object attributes on a given accessible.
  */
diff --git a/accessible/base/AccTypes.h b/accessible/base/AccTypes.h
index 3e9d88e486..76fdaae2d7 100644
--- a/accessible/base/AccTypes.h
+++ b/accessible/base/AccTypes.h
@@ -87,6 +87,7 @@ enum AccGenericType {
   eText = 1 << 14,
   eNumericValue = 1 << 15,
   eActionable = 1 << 16,  // This is for remote accessibles
+  eDPub = 1 << 17,
 
   eLastAccGenericType = eActionable,
   eAllGenericTypes = (eLastAccGenericType << 1) - 1
diff --git a/accessible/base/nsAccessibilityService.cpp b/accessible/base/nsAccessibilityService.cpp
index 615af596a7..7b5f127672 100644
--- a/accessible/base/nsAccessibilityService.cpp
+++ b/accessible/base/nsAccessibilityService.cpp
@@ -12,6 +12,7 @@
 #include "DocAccessible-inl.h"
 #include "DocAccessibleChild.h"
 #include "FocusManager.h"
+#include "mozilla/FocusModel.h"
 #include "HTMLCanvasAccessible.h"
 #include "HTMLElementAccessibles.h"
 #include "HTMLImageMapAccessible.h"
@@ -136,48 +137,6 @@ static LocalAccessible* MaybeCreateSpecificARIAAccessible(
 }
 
 /**
- * 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;
@@ -224,19 +183,53 @@ static bool MustBeGenericAccessible(nsIContent* aContent,
  * 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;
+  if (nsIFrame* frame = aContent->GetPrimaryFrame()) {
+    // 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(IsFocusableFlags::IgnoreVisibility)) {
+      return true;
+    }
+  }
+
+  // Return true if the element has an attribute (ARIA, title, or relation) that
+  // requires the creation of an Accessible for the element.
+  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 AttributesMustBeAccessible(aContent, aDocument);
+  return false;
 }
 
 bool nsAccessibilityService::ShouldCreateImgAccessible(
@@ -294,6 +287,38 @@ static bool MustSVGElementBeAccessible(nsIContent* aContent,
 }
 
 /**
+ * Return an accessible for the content if the SVG element requires the creation
+ * of an Accessible.
+ */
+static RefPtr<LocalAccessible> MaybeCreateSVGAccessible(
+    nsIContent* aContent, DocAccessible* aDocument) {
+  if (aContent->IsSVGGeometryElement() ||
+      aContent->IsSVGElement(nsGkAtoms::image)) {
+    // Shape elements: rect, circle, ellipse, line, path, polygon, and polyline.
+    // 'use' and 'text' graphic elements require special support.
+    if (MustSVGElementBeAccessible(aContent, aDocument)) {
+      return new EnumRoleAccessible<roles::GRAPHIC>(aContent, aDocument);
+    }
+  } else if (aContent->IsSVGElement(nsGkAtoms::text)) {
+    return new HyperTextAccessible(aContent->AsElement(), aDocument);
+  } else if (aContent->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.
+    return new EnumRoleHyperTextAccessible<roles::DIAGRAM>(aContent, aDocument);
+  } else if (aContent->IsSVGElement(nsGkAtoms::g) &&
+             MustSVGElementBeAccessible(aContent, aDocument)) {
+    // <g> can also contain <foreignObject>.
+    return new EnumRoleHyperTextAccessible<roles::GROUPING>(aContent,
+                                                            aDocument);
+  } else if (aContent->IsSVGElement(nsGkAtoms::a)) {
+    return new HTMLLinkAccessible(aContent, aDocument);
+  }
+  return nullptr;
+}
+
+/**
  * Used by XULMap.h to map both menupopup and popup elements
  */
 LocalAccessible* CreateMenupopupAccessible(Element* aElement,
@@ -1138,13 +1163,19 @@ LocalAccessible* nsAccessibilityService::CreateAccessible(
       }
     }
 
+    // SVG elements are not in a markup map, but we may still need to create an
+    // accessible for one, even in the case of display:contents.
+    if (!newAcc && content->IsSVGElement()) {
+      newAcc = MaybeCreateSVGAccessible(content, document);
+    }
+
     // 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))) {
+    if (!newAcc &&
+        (hasNonPresentationalARIARole || MustBeAccessible(content, document))) {
       newAcc = new HyperTextAccessible(content, document);
     }
 
@@ -1365,32 +1396,7 @@ LocalAccessible* nsAccessibilityService::CreateAccessible(
 
   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 HyperTextAccessible(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);
-      }
-
+      newAcc = MaybeCreateSVGAccessible(content, document);
     } else if (content->IsMathMLElement()) {
       const MarkupMapInfo* markupMap =
           mMathMLMarkupMap.Get(content->NodeInfo()->NameAtom());
diff --git a/accessible/base/nsCoreUtils.cpp b/accessible/base/nsCoreUtils.cpp
index c5e89258fa..3e66fa9c23 100644
--- a/accessible/base/nsCoreUtils.cpp
+++ b/accessible/base/nsCoreUtils.cpp
@@ -547,32 +547,6 @@ bool nsCoreUtils::IsWhitespaceString(const nsAString& aString) {
   return iterBegin == iterEnd;
 }
 
-void nsCoreUtils::TrimNonBreakingSpaces(nsAString& aString) {
-  if (aString.IsEmpty()) {
-    return;
-  }
-
-  // Find the index past the last nbsp prefix character.
-  constexpr char16_t nbsp{0xA0};
-  size_t startIndex = 0;
-  while (aString.CharAt(startIndex) == nbsp) {
-    startIndex++;
-  }
-
-  // Find the index before the first nbsp suffix character.
-  size_t endIndex = aString.Length() - 1;
-  while (endIndex > startIndex && aString.CharAt(endIndex) == nbsp) {
-    endIndex--;
-  }
-  if (startIndex > endIndex) {
-    aString.Truncate();
-    return;
-  }
-
-  // Trim the string down, removing the non-breaking space characters.
-  aString = Substring(aString, startIndex, endIndex - startIndex + 1);
-}
-
 bool nsCoreUtils::AccEventObserversExist() {
   nsCOMPtr<nsIObserverService> obsService = services::GetObserverService();
   NS_ENSURE_TRUE(obsService, false);
diff --git a/accessible/base/nsCoreUtils.h b/accessible/base/nsCoreUtils.h
index 5e77d6bfe0..28ead982af 100644
--- a/accessible/base/nsCoreUtils.h
+++ b/accessible/base/nsCoreUtils.h
@@ -307,11 +307,6 @@ class nsCoreUtils {
            aChar == 0xa0;
   }
 
-  /**
-   * Remove non-breaking spaces from the beginning and end of the string.
-   */
-  static void TrimNonBreakingSpaces(nsAString& aString);
-
   /*
    * Return true if there are any observers of accessible events.
    */
diff --git a/accessible/basetypes/Accessible.cpp b/accessible/basetypes/Accessible.cpp
index 8b433a0ddd..234c7aa4a1 100644
--- a/accessible/basetypes/Accessible.cpp
+++ b/accessible/basetypes/Accessible.cpp
@@ -508,6 +508,24 @@ const Accessible* Accessible::ActionAncestor() const {
 }
 
 nsStaticAtom* Accessible::LandmarkRole() const {
+  // For certain cases below (e.g. ARIA region, HTML <header>), whether it is
+  // actually a landmark is conditional. Rather than duplicating that
+  // conditional logic here, we check the Gecko role.
+  if (const nsRoleMapEntry* roleMapEntry = ARIARoleMap()) {
+    // Explicit ARIA role should take precedence.
+    if (roleMapEntry->Is(nsGkAtoms::region)) {
+      if (Role() == roles::REGION) {
+        return nsGkAtoms::region;
+      }
+    } else if (roleMapEntry->Is(nsGkAtoms::form)) {
+      if (Role() == roles::FORM) {
+        return nsGkAtoms::form;
+      }
+    } else if (roleMapEntry->IsOfType(eLandmark)) {
+      return roleMapEntry->roleAtom;
+    }
+  }
+
   nsAtom* tagName = TagName();
   if (!tagName) {
     // Either no associated content, or no cache.
@@ -539,13 +557,13 @@ nsStaticAtom* Accessible::LandmarkRole() const {
   }
 
   if (tagName == nsGkAtoms::section) {
-    if (!NameIsEmpty()) {
+    if (Role() == roles::REGION) {
       return nsGkAtoms::region;
     }
   }
 
   if (tagName == nsGkAtoms::form) {
-    if (!NameIsEmpty()) {
+    if (Role() == roles::FORM_LANDMARK) {
       return nsGkAtoms::form;
     }
   }
@@ -554,14 +572,14 @@ nsStaticAtom* Accessible::LandmarkRole() const {
     return nsGkAtoms::search;
   }
 
-  const nsRoleMapEntry* roleMapEntry = ARIARoleMap();
-  return roleMapEntry && roleMapEntry->IsOfType(eLandmark)
-             ? roleMapEntry->roleAtom
-             : nullptr;
+  return nullptr;
 }
 
 nsStaticAtom* Accessible::ComputedARIARole() const {
   const nsRoleMapEntry* roleMap = ARIARoleMap();
+  if (roleMap && roleMap->IsOfType(eDPub)) {
+    return roleMap->roleAtom;
+  }
   if (roleMap && roleMap->roleAtom != nsGkAtoms::_empty &&
       // region and form have their own Gecko roles and need to be handled
       // specially.
@@ -605,12 +623,15 @@ void Accessible::ApplyImplicitState(uint64_t& aState) const {
     }
   }
 
-  // If this is an ARIA item of the selectable widget and if it's focused and
-  // not marked unselected explicitly (i.e. aria-selected="false") then expose
-  // it as selected to make ARIA widget authors life easier.
+  // If this is an option, tab or treeitem and if it's focused and not marked
+  // unselected explicitly (i.e. aria-selected="false") then expose it as
+  // selected to make ARIA widget authors life easier.
   const nsRoleMapEntry* roleMapEntry = ARIARoleMap();
-  if (roleMapEntry && !(aState & states::SELECTED) &&
-      ARIASelected().valueOr(true)) {
+  if (roleMapEntry &&
+      (roleMapEntry->Is(nsGkAtoms::option) ||
+       roleMapEntry->Is(nsGkAtoms::tab) ||
+       roleMapEntry->Is(nsGkAtoms::treeitem)) &&
+      !(aState & states::SELECTED) && ARIASelected().valueOr(true)) {
     // Special case for tabs: focused tab or focus inside related tab panel
     // implies selected state.
     if (roleMapEntry->role == roles::PAGETAB) {
diff --git a/accessible/basetypes/Accessible.h b/accessible/basetypes/Accessible.h
index 9068115d01..1848fc6b37 100644
--- a/accessible/basetypes/Accessible.h
+++ b/accessible/basetypes/Accessible.h
@@ -438,10 +438,15 @@ class Accessible {
   nsStaticAtom* LandmarkRole() const;
 
   /**
-   * Return the id of the dom node this accessible represents.
+   * Return the id of the DOM node this Accessible represents.
    */
   virtual void DOMNodeID(nsString& aID) const = 0;
 
+  /**
+   * Return the class of the DOM node this Accessible represents.
+   */
+  virtual void DOMNodeClass(nsString& aClass) const = 0;
+
   //////////////////////////////////////////////////////////////////////////////
   // ActionAccessible
 
diff --git a/accessible/docs/index.rst b/accessible/docs/index.rst
index 881d49ca9b..5626eb1dbc 100644
--- a/accessible/docs/index.rst
+++ b/accessible/docs/index.rst
@@ -6,6 +6,8 @@ They live in the mozilla-central repository under the accessible/docs directory.
 
 The `Accessibility page on the Mozilla Wiki <https://wiki.mozilla.org/Accessibility>`__ contains general information about accessibility and the accessibility team at Mozilla.
 
+The `Mochitest FAQ docs <../testing/mochitest-plain/faq.html#how-can-i-run-accessibility-tests-a11y-checks>`__ contain guidance on debugging a11y-checks failures and working with AccessibilityUtils when writing frontend test cases.
+
 .. toctree::
    :maxdepth: 1
 
diff --git a/accessible/generic/LocalAccessible.cpp b/accessible/generic/LocalAccessible.cpp
index aaf0337a1a..b01b758945 100644
--- a/accessible/generic/LocalAccessible.cpp
+++ b/accessible/generic/LocalAccessible.cpp
@@ -14,6 +14,7 @@
 #include "mozilla/a11y/AccAttributes.h"
 #include "mozilla/a11y/DocAccessibleChild.h"
 #include "mozilla/a11y/Platform.h"
+#include "mozilla/FocusModel.h"
 #include "nsAccUtils.h"
 #include "nsAccessibilityService.h"
 #include "ApplicationAccessible.h"
@@ -127,7 +128,6 @@ ENameValueFlag LocalAccessible::Name(nsString& aName) const {
   if (!aName.IsEmpty()) return eNameOK;
 
   ENameValueFlag nameFlag = NativeName(aName);
-  nsCoreUtils::TrimNonBreakingSpaces(aName);
   if (!aName.IsEmpty()) return nameFlag;
 
   // In the end get the name from tooltip.
@@ -408,6 +408,7 @@ uint64_t LocalAccessible::NativeInteractiveState() const {
   if (NativelyUnavailable()) return states::UNAVAILABLE;
 
   nsIFrame* frame = GetFrame();
+  auto flags = IsFocusableFlags(0);
   // If we're caching this remote document in the parent process, we
   // need to cache focusability irrespective of visibility. Otherwise,
   // if this document is invisible when it first loads, we'll cache that
@@ -418,13 +419,12 @@ uint64_t LocalAccessible::NativeInteractiveState() const {
   // Although ignoring visibility means IsFocusable will return true for
   // visibility: hidden, etc., this isn't a problem because we don't include
   // those hidden elements in the a11y tree anyway.
-  const bool ignoreVisibility = mDoc->IPCDoc();
-  if (frame && frame->IsFocusable(
-                   /* aWithMouse */ false,
-                   /* aCheckVisibility */ !ignoreVisibility)) {
+  if (mDoc->IPCDoc()) {
+    flags |= IsFocusableFlags::IgnoreVisibility;
+  }
+  if (frame && frame->IsFocusable(flags)) {
     return states::FOCUSABLE;
   }
-
   return 0;
 }
 
@@ -689,7 +689,8 @@ nsRect LocalAccessible::RelativeBounds(nsIFrame** aBoundingFrame) const {
   if (frame && mContent) {
     *aBoundingFrame = nsLayoutUtils::GetContainingBlockForClientRect(frame);
     nsRect unionRect = nsLayoutUtils::GetAllInFlowRectsUnion(
-        frame, *aBoundingFrame, nsLayoutUtils::RECTS_ACCOUNT_FOR_TRANSFORMS);
+        frame, *aBoundingFrame,
+        nsLayoutUtils::GetAllInFlowRectsFlag::AccountForTransforms);
 
     if (unionRect.IsEmpty()) {
       // If we end up with a 0x0 rect from above (or one with negative
@@ -1625,6 +1626,14 @@ void LocalAccessible::ApplyARIAState(uint64_t* aState) const {
   *aState |= aria::UniversalStatesFor(element);
 
   const nsRoleMapEntry* roleMapEntry = ARIARoleMap();
+  if (!roleMapEntry && IsHTMLTableCell() && Role() == roles::GRID_CELL) {
+    // This is a <td> inside a role="grid", so it gets an implicit role of
+    // GRID_CELL in ARIATransformRole. However, because it's implicit, we
+    // don't have a role map entry, and without that, we can't apply ARIA states
+    // below. Therefore, we get the role map entry here.
+    roleMapEntry = aria::GetRoleMap(nsGkAtoms::gridcell);
+    MOZ_ASSERT(roleMapEntry, "Should have role map entry for gridcell");
+  }
   if (roleMapEntry) {
     // We only force the readonly bit off if we have a real mapping for the aria
     // role. This preserves the ability for screen readers to use readonly
@@ -3794,14 +3803,12 @@ already_AddRefed<AccAttributes> LocalAccessible::BundleFieldsForCache(
     } else if (aUpdateType == CacheUpdateType::Update) {
       fields->SetAttribute(CacheKey::DOMNodeID, DeleteEntry());
     }
-    if (auto* el = dom::Element::FromNodeOrNull(mContent)) {
-      nsAutoString className;
-      el->GetClassName(className);
-      if (!className.IsEmpty()) {
-        fields->SetAttribute(CacheKey::DOMNodeClass, std::move(className));
-      } else if (aUpdateType == CacheUpdateType::Update) {
-        fields->SetAttribute(CacheKey::DOMNodeClass, DeleteEntry());
-      }
+    nsString className;
+    DOMNodeClass(className);
+    if (!className.IsEmpty()) {
+      fields->SetAttribute(CacheKey::DOMNodeClass, std::move(className));
+    } else if (aUpdateType == CacheUpdateType::Update) {
+      fields->SetAttribute(CacheKey::DOMNodeClass, DeleteEntry());
     }
   }
 
@@ -4272,6 +4279,13 @@ void LocalAccessible::DOMNodeID(nsString& aID) const {
   }
 }
 
+void LocalAccessible::DOMNodeClass(nsString& aClass) const {
+  aClass.Truncate();
+  if (auto* el = dom::Element::FromNodeOrNull(mContent)) {
+    el->GetClassName(aClass);
+  }
+}
+
 void LocalAccessible::LiveRegionAttributes(nsAString* aLive,
                                            nsAString* aRelevant,
                                            Maybe<bool>* aAtomic,
diff --git a/accessible/generic/LocalAccessible.h b/accessible/generic/LocalAccessible.h
index 51c4cc9424..eb684b9291 100644
--- a/accessible/generic/LocalAccessible.h
+++ b/accessible/generic/LocalAccessible.h
@@ -736,6 +736,8 @@ class LocalAccessible : public nsISupports, public Accessible {
 
   virtual void DOMNodeID(nsString& aID) const override;
 
+  virtual void DOMNodeClass(nsString& aClass) const override;
+
   virtual void LiveRegionAttributes(nsAString* aLive, nsAString* aRelevant,
                                     Maybe<bool>* aAtomic,
                                     nsAString* aBusy) const override;
diff --git a/accessible/ipc/DocAccessibleChild.h b/accessible/ipc/DocAccessibleChild.h
index 0a6164cce8..01673ba689 100644
--- a/accessible/ipc/DocAccessibleChild.h
+++ b/accessible/ipc/DocAccessibleChild.h
@@ -24,7 +24,9 @@ class AccShowEvent;
  */
 class DocAccessibleChild : public PDocAccessibleChild {
  public:
-  DocAccessibleChild(DocAccessible* aDoc, IProtocol* aManager) : mDoc(aDoc) {
+  DocAccessibleChild(DocAccessible* aDoc,
+                     mozilla::ipc::IRefCountedProtocol* aManager)
+      : mDoc(aDoc) {
     MOZ_COUNT_CTOR(DocAccessibleChild);
     SetManager(aManager);
   }
diff --git a/accessible/ipc/RemoteAccessible.cpp b/accessible/ipc/RemoteAccessible.cpp
index 772fc58776..0077750ed3 100644
--- a/accessible/ipc/RemoteAccessible.cpp
+++ b/accessible/ipc/RemoteAccessible.cpp
@@ -1329,6 +1329,13 @@ void RemoteAccessible::DOMNodeID(nsString& aID) const {
   }
 }
 
+void RemoteAccessible::DOMNodeClass(nsString& aClass) const {
+  if (mCachedFields) {
+    mCachedFields->GetAttribute(CacheKey::DOMNodeClass, aClass);
+    VERIFY_CACHE(CacheDomain::DOMNodeIDAndClass);
+  }
+}
+
 void RemoteAccessible::ScrollToPoint(uint32_t aScrollType, int32_t aX,
                                      int32_t aY) {
   Unused << mDoc->SendScrollToPoint(mID, aScrollType, aX, aY);
@@ -1551,7 +1558,7 @@ already_AddRefed<AccAttributes> RemoteAccessible::Attributes() {
     }
 
     nsString className;
-    mCachedFields->GetAttribute(CacheKey::DOMNodeClass, className);
+    DOMNodeClass(className);
     if (!className.IsEmpty()) {
       attributes->SetAttribute(nsGkAtoms::_class, std::move(className));
     }
diff --git a/accessible/ipc/RemoteAccessible.h b/accessible/ipc/RemoteAccessible.h
index 9215fd7bc5..45f41b8fb5 100644
--- a/accessible/ipc/RemoteAccessible.h
+++ b/accessible/ipc/RemoteAccessible.h
@@ -365,6 +365,8 @@ class RemoteAccessible : public Accessible, public HyperTextAccessibleBase {
 
   virtual void DOMNodeID(nsString& aID) const override;
 
+  virtual void DOMNodeClass(nsString& aClass) const override;
+
   virtual void ScrollToPoint(uint32_t aScrollType, int32_t aX,
                              int32_t aY) override;
 
diff --git a/accessible/mac/AccessibleWrap.mm b/accessible/mac/AccessibleWrap.mm
index ef2f4ba779..e8107b1690 100644
--- a/accessible/mac/AccessibleWrap.mm
+++ b/accessible/mac/AccessibleWrap.mm
@@ -192,6 +192,9 @@ Class a11y::GetTypeFromRole(roles::Role aRole) {
     case roles::RADIO_MENU_ITEM:
       return [mozRadioButtonAccessible class];
 
+    case roles::PROGRESSBAR:
+      return [mozRangeAccessible class];
+
     case roles::SPINBUTTON:
     case roles::SLIDER:
       return [mozIncrementableAccessible class];
diff --git a/accessible/mac/MOXWebAreaAccessible.mm b/accessible/mac/MOXWebAreaAccessible.mm
index c1ae585fa1..37168b1be2 100644
--- a/accessible/mac/MOXWebAreaAccessible.mm
+++ b/accessible/mac/MOXWebAreaAccessible.mm
@@ -211,7 +211,7 @@ using namespace mozilla::a11y;
 
 - (NSArray*)moxUnignoredChildren {
   if (id rootGroup = [self rootGroup]) {
-    return @[ [self rootGroup] ];
+    return @[ rootGroup ];
   }
 
   // There is no root group, expose the children here directly.
diff --git a/accessible/mac/mozActionElements.h b/accessible/mac/mozActionElements.h
index f9940c793a..d5b286ff97 100644
--- a/accessible/mac/mozActionElements.h
+++ b/accessible/mac/mozActionElements.h
@@ -65,15 +65,14 @@
 @end
 
 /**
- * Base accessible for an incrementable
+ * Base accessible for a range, an acc with a min, max that cannot
+ * be modified by the user directly.
  */
-@interface mozIncrementableAccessible : mozAccessible
 
-// override
-- (id)moxValue;
+@interface mozRangeAccessible : mozAccessible
 
 // override
-- (NSString*)moxValueDescription;
+- (id)moxValue;
 
 // override
 - (id)moxMinValue;
@@ -82,19 +81,29 @@
 - (id)moxMaxValue;
 
 // override
-- (void)moxSetValue:(id)value;
+- (NSString*)moxOrientation;
 
 // override
-- (void)moxPerformIncrement;
+- (void)handleAccessibleEvent:(uint32_t)eventType;
+
+@end
+
+/**
+ * Base accessible for an incrementable, a settable range
+ */
+@interface mozIncrementableAccessible : mozRangeAccessible
 
 // override
-- (void)moxPerformDecrement;
+- (NSString*)moxValueDescription;
 
 // override
-- (NSString*)moxOrientation;
+- (void)moxSetValue:(id)value;
 
 // override
-- (void)handleAccessibleEvent:(uint32_t)eventType;
+- (void)moxPerformIncrement;
+
+// override
+- (void)moxPerformDecrement;
 
 - (void)changeValueBySteps:(int)factor;
 
diff --git a/accessible/mac/mozActionElements.mm b/accessible/mac/mozActionElements.mm
index f39f2c8ad5..e3a2ff9598 100644
--- a/accessible/mac/mozActionElements.mm
+++ b/accessible/mac/mozActionElements.mm
@@ -134,17 +134,12 @@ using namespace mozilla::a11y;
 
 @end
 
-@implementation mozIncrementableAccessible
+@implementation mozRangeAccessible
 
 - (id)moxValue {
   return [NSNumber numberWithDouble:mGeckoAccessible->CurValue()];
 }
 
-- (NSString*)moxValueDescription {
-  nsAutoString valueDesc;
-  mGeckoAccessible->Value(valueDesc);
-  return nsCocoaUtils::ToNSString(valueDesc);
-}
 - (id)moxMinValue {
   return [NSNumber numberWithDouble:mGeckoAccessible->MinValue()];
 }
@@ -153,18 +148,6 @@ using namespace mozilla::a11y;
   return [NSNumber numberWithDouble:mGeckoAccessible->MaxValue()];
 }
 
-- (void)moxSetValue:(id)value {
-  [self setValue:([value doubleValue])];
-}
-
-- (void)moxPerformIncrement {
-  [self changeValueBySteps:1];
-}
-
-- (void)moxPerformDecrement {
-  [self changeValueBySteps:-1];
-}
-
 - (NSString*)moxOrientation {
   RefPtr<AccAttributes> attributes = mGeckoAccessible->Attributes();
   if (attributes) {
@@ -192,6 +175,28 @@ using namespace mozilla::a11y;
   }
 }
 
+@end
+
+@implementation mozIncrementableAccessible
+
+- (NSString*)moxValueDescription {
+  nsAutoString valueDesc;
+  mGeckoAccessible->Value(valueDesc);
+  return nsCocoaUtils::ToNSString(valueDesc);
+}
+
+- (void)moxSetValue:(id)value {
+  [self setValue:([value doubleValue])];
+}
+
+- (void)moxPerformIncrement {
+  [self changeValueBySteps:1];
+}
+
+- (void)moxPerformDecrement {
+  [self changeValueBySteps:-1];
+}
+
 /*
  * Updates the accessible's current value by factor and step.
  *
diff --git a/accessible/tests/browser/e10s/browser.toml b/accessible/tests/browser/e10s/browser.toml
index dff9b1c712..a4205d38e6 100644
--- a/accessible/tests/browser/e10s/browser.toml
+++ b/accessible/tests/browser/e10s/browser.toml
@@ -31,6 +31,7 @@ prefs = [
 ["browser_caching_description.js"]
 
 ["browser_caching_document_props.js"]
+https_first_disabled = true
 
 ["browser_caching_domnodeid.js"]
 
diff --git a/accessible/tests/browser/e10s/browser_caching_states.js b/accessible/tests/browser/e10s/browser_caching_states.js
index 7292228f25..6f674f8c48 100644
--- a/accessible/tests/browser/e10s/browser_caching_states.js
+++ b/accessible/tests/browser/e10s/browser_caching_states.js
@@ -425,6 +425,11 @@ addAccessibleTask(
 <div role="listbox" aria-multiselectable="true">
   <div id="multiNoSel" role="option" tabindex="0">multiNoSel</div>
 </div>
+<div role="grid">
+  <div role="row">
+    <div id="gridcell" role="gridcell" tabindex="0">gridcell</div>
+  </div>
+</div>
   `,
   async function (browser, docAcc) {
     const noSel = findAccessibleChildByID(docAcc, "noSel");
@@ -450,6 +455,14 @@ addAccessibleTask(
     multiNoSel.takeFocus();
     await focused;
     testStates(multiNoSel, STATE_FOCUSED, 0, STATE_SELECTED, 0);
+
+    const gridcell = findAccessibleChildByID(docAcc, "gridcell");
+    testStates(gridcell, 0, 0, STATE_FOCUSED | STATE_SELECTED, 0);
+    info("Focusing gridcell");
+    focused = waitForEvent(EVENT_FOCUS, gridcell);
+    gridcell.takeFocus();
+    await focused;
+    testStates(gridcell, STATE_FOCUSED, 0, STATE_SELECTED, 0);
   },
   { topLevel: true, iframe: true, remoteIframe: true, chrome: true }
 );
diff --git a/accessible/tests/browser/e10s/head.js b/accessible/tests/browser/e10s/head.js
index bdbcb7445f..e72af914d4 100644
--- a/accessible/tests/browser/e10s/head.js
+++ b/accessible/tests/browser/e10s/head.js
@@ -170,6 +170,11 @@ async function testRelated(
       expected: [null, host, dependant2],
     },
     {
+      desc: "Change attribute to multiple targets",
+      attrs: [{ key: attr, value: "dependant1 dependant2" }],
+      expected: [host, host, [dependant1, dependant2]],
+    },
+    {
       desc: "Remove attribute",
       attrs: [{ key: attr }],
       expected: [null, null, null],
diff --git a/accessible/tests/browser/mac/browser_range.js b/accessible/tests/browser/mac/browser_range.js
index 430e41d6ea..8a5bafba50 100644
--- a/accessible/tests/browser/mac/browser_range.js
+++ b/accessible/tests/browser/mac/browser_range.js
@@ -188,3 +188,57 @@ addAccessibleTask(
     is(slider.getAttributeValue("AXMaxValue"), 5, "Correct max value");
   }
 );
+
+/**
+ * Verify progress HTML elements expose their min, max, and value to VO.
+ * Progress elements should not expose a value description, and should not
+ * expose increment/decrement actions.
+ */
+addAccessibleTask(
+  `<progress id="progress" value="70" max="100"></progress>`,
+  async (browser, accDoc) => {
+    const progress = getNativeInterface(accDoc, "progress");
+    is(progress.getAttributeValue("AXValue"), 70, "Correct value");
+    is(progress.getAttributeValue("AXMaxValue"), 100, "Correct max value");
+    is(progress.getAttributeValue("AXMinValue"), 0, "Correct min value");
+    is(
+      progress.getAttributeValue("AXValueDescription"),
+      null,
+      "Progress elements should not expose a value description"
+    );
+    for (let action of progress.actionNames) {
+      isnot(
+        action,
+        "AXIncrement",
+        "Progress elements should not expose increment action"
+      );
+      isnot(
+        action,
+        "AXDecrement",
+        "Progress elements should not expose decrement action"
+      );
+    }
+  }
+);
+
+/**
+ * Verify progress HTML elements expose changes to their value.
+ */
+addAccessibleTask(
+  `<progress id="progress" value="70" max="100"></progress>`,
+  async (browser, accDoc) => {
+    const progress = getNativeInterface(accDoc, "progress");
+    is(progress.getAttributeValue("AXValue"), 70, "Correct value");
+    is(progress.getAttributeValue("AXMaxValue"), 100, "Correct max value");
+    is(progress.getAttributeValue("AXMinValue"), 0, "Correct min value");
+
+    const evt = waitForMacEvent("AXValueChanged");
+    await invokeContentTask(browser, [], () => {
+      const p = content.document.getElementById("progress");
+      p.setAttribute("value", "90");
+    });
+    await evt;
+
+    is(progress.getAttributeValue("AXValue"), 90, "Correct updated value");
+  }
+);
diff --git a/accessible/tests/browser/python_runner_wsh.py b/accessible/tests/browser/python_runner_wsh.py
index 488051240f..2686967cfb 100644
--- a/accessible/tests/browser/python_runner_wsh.py
+++ b/accessible/tests/browser/python_runner_wsh.py
@@ -9,6 +9,7 @@ It is intended to be called from JS browser tests.
 """
 
 import json
+import math
 import os
 import sys
 import traceback
@@ -83,6 +84,9 @@ def web_socket_transfer_data(request):
             exec(code, namespace)
             # Run the function we just defined.
             ret = namespace["run"]()
+            if isinstance(ret, float) and math.isnan(ret):
+                # NaN can't be serialized by JSON.
+                ret = None
             send("return", ret)
         except Exception:
             send("exception", traceback.format_exc())
diff --git a/accessible/tests/browser/selectable/browser_test_aria_select.js b/accessible/tests/browser/selectable/browser_test_aria_select.js
index dbc36956f8..2c3a80586e 100644
--- a/accessible/tests/browser/selectable/browser_test_aria_select.js
+++ b/accessible/tests/browser/selectable/browser_test_aria_select.js
@@ -117,7 +117,8 @@ addAccessibleTask(
 // ////////////////////////////////////////////////////////////////////////
 // role="grid" aria-multiselectable, selectable children in subtree
 addAccessibleTask(
-  `<table tabindex="0" border="2" cellspacing="0" id="grid" role="grid"
+  `
+  <table tabindex="0" border="2" cellspacing="0" id="grid" role="grid"
       aria-multiselectable="true">
     <thead>
       <tr>
@@ -133,19 +134,29 @@ addAccessibleTask(
       <tr>
         <td tabindex="-1" role="rowheader" id="grid_rowhead"
             aria-readonly="true">1</td>
-        <td tabindex="-1" role="gridcell" id="grid_cell1"
+        <td tabindex="-1" id="grid_cell1"
             aria-selected="true">03/14/05</td>
-        <td tabindex="-1" role="gridcell" id="grid_cell2"
+        <td tabindex="-1" id="grid_cell2"
             aria-selected="false">Conference Fee</td>
       </tr>
-    </tobdy>
-  </table>`,
+    </tbody>
+  </table>
+  <table id="table">
+    <tr><th>a</th><td id="tableB" aria-selected="true">b</td></tr>
+  </table>
+  `,
   async function (browser, docAcc) {
     info('role="grid" aria-multiselectable, selectable children in subtree');
-    let grid = findAccessibleChildByID(docAcc, "grid", [
+    const grid = findAccessibleChildByID(docAcc, "grid", [
       nsIAccessibleSelectable,
     ]);
+    // grid_cell1 is a <td> with an implicit role of gridcell.
     testSelectableSelection(grid, ["grid_colhead1", "grid_cell1"]);
+    info("Verify aria-selected doesn't apply to <td> that isn't gridcell");
+    // We can't use testSelectableSelection here because table (rightly) isn't a
+    // selectable container.
+    const tableB = findAccessibleChildByID(docAcc, "tableB");
+    testStates(tableB, 0, 0, STATE_SELECTED, 0);
   },
   {
     chrome: true,
diff --git a/accessible/tests/browser/windows/uia/browser.toml b/accessible/tests/browser/windows/uia/browser.toml
index 75728f56d7..13b1c12cc0 100644
--- a/accessible/tests/browser/windows/uia/browser.toml
+++ b/accessible/tests/browser/windows/uia/browser.toml
@@ -11,8 +11,15 @@ support-files = ["head.js"]
 ["browser_elementFromPoint.js"]
 
 ["browser_focus.js"]
+
 ["browser_generalProps.js"]
 
+["browser_gridPatterns.js"]
+
+["browser_relationProps.js"]
+
+["browser_selectionPatterns.js"]
+
 ["browser_simplePatterns.js"]
 
 ["browser_tree.js"]
diff --git a/accessible/tests/browser/windows/uia/browser_generalProps.js b/accessible/tests/browser/windows/uia/browser_generalProps.js
index 5cfda226d0..244c9e4b1b 100644
--- a/accessible/tests/browser/windows/uia/browser_generalProps.js
+++ b/accessible/tests/browser/windows/uia/browser_generalProps.js
@@ -4,6 +4,12 @@
 
 "use strict";
 
+/* eslint-disable camelcase */
+// From https://learn.microsoft.com/en-us/windows/win32/winauto/landmark-type-identifiers
+const UIA_CustomLandmarkTypeId = 80000;
+const UIA_MainLandmarkTypeId = 80002;
+/* eslint-enable camelcase */
+
 /**
  * Test the Name property.
  */
@@ -103,3 +109,347 @@ addUiaTask(
     ok(await runPython(`p.CurrentIsEnabled`), "p has IsEnabled true");
   }
 );
+
+async function testGroupPos(id, level, pos, size) {
+  await assignPyVarToUiaWithId(id);
+  is(await runPython(`${id}.CurrentLevel`), level, `${id} Level correct`);
+  is(
+    await runPython(`${id}.CurrentPositionInSet`),
+    pos,
+    `${id} PositionInSet correct`
+  );
+  is(
+    await runPython(`${id}.CurrentSizeOfSet`),
+    size,
+    `${id} SizeOfSet correct`
+  );
+}
+
+/**
+ * Test the Level, PositionInSet and SizeOfSet properties.
+ */
+addUiaTask(
+  `
+<ul>
+  <li id="li1">li1<ul id="ul1">
+    <li id="li2a">li2a</li>
+    <li id="li2b" hidden>li2b</li>
+    <li id="li2c">li2c</li>
+  </ul></li>
+</ul>
+<h2 id="h2">h2</h2>
+<button id="button">button</button>
+  `,
+  async function testGroupPosProps(browser) {
+    await definePyVar("doc", `getDocUia()`);
+    await testGroupPos("li1", 1, 1, 1);
+    await testGroupPos("li2a", 2, 1, 2);
+    await testGroupPos("li2c", 2, 2, 2);
+    info("Showing li2b");
+    // There aren't events in any API for a change to group position properties
+    // because this would be too spammy and isn't particularly useful given
+    // how frequently these can change.
+    let shown = waitForEvent(EVENT_SHOW, "li2b");
+    await invokeContentTask(browser, [], () => {
+      content.document.getElementById("li2b").hidden = false;
+    });
+    await shown;
+    await testGroupPos("li2a", 2, 1, 3);
+    await testGroupPos("li2b", 2, 2, 3);
+    await testGroupPos("li2c", 2, 3, 3);
+
+    // The IA2 -> UIA proxy doesn't map heading level to the Level property.
+    if (gIsUiaEnabled) {
+      await testGroupPos("h2", 2, 0, 0);
+    }
+    await testGroupPos("button", 0, 0, 0);
+  }
+);
+
+/**
+ * Test the FrameworkId property.
+ */
+addUiaTask(
+  `<button id="button">button</button>`,
+  async function testFrameworkId() {
+    await definePyVar("doc", `getDocUia()`);
+    is(
+      await runPython(`doc.CurrentFrameworkId`),
+      "Gecko",
+      "doc FrameworkId is correct"
+    );
+    await assignPyVarToUiaWithId("button");
+    is(
+      await runPython(`button.CurrentFrameworkId`),
+      "Gecko",
+      "button FrameworkId is correct"
+    );
+  }
+);
+
+/**
+ * Test the ClassName property.
+ */
+addUiaTask(
+  `
+<p id="p">p</p>
+<button id="button" class="c1">button</button>
+  `,
+  async function testClassName(browser, docAcc) {
+    await definePyVar("doc", `getDocUia()`);
+    await assignPyVarToUiaWithId("p");
+    ok(!(await runPython(`p.CurrentClassName`)), "p has no ClassName");
+
+    await assignPyVarToUiaWithId("button");
+    is(
+      await runPython(`button.CurrentClassName`),
+      "c1",
+      "button has correct ClassName"
+    );
+    info("Changing button class");
+    await invokeSetAttribute(browser, "button", "class", "c2 c3");
+    // Gecko doesn't fire an event for class changes, as this isn't useful for
+    // clients.
+    const button = findAccessibleChildByID(docAcc, "button");
+    await untilCacheIs(
+      () => button.attributes.getStringProperty("class"),
+      "c2 c3",
+      "button class updated"
+    );
+    is(
+      await runPython(`button.CurrentClassName`),
+      "c2 c3",
+      "button has correct ClassName"
+    );
+  },
+  // The IA2 -> UIA proxy doesn't support ClassName.
+  { uiaEnabled: true, uiaDisabled: false }
+);
+
+/**
+ * Test the AriaRole property.
+ */
+addUiaTask(
+  `
+<div id="button" role="button">button</div>
+<div id="main" role="main">main</div>
+<div id="unknown" role="unknown">unknown</div>
+<button id="computedButton">computedButton</button>
+<h1 id="computedHeading">computedHeading</h1>
+<main id="computedMain">computedMain</main>
+<div id="generic">generic</div>
+  `,
+  async function testAriaRole() {
+    await definePyVar("doc", `getDocUia()`);
+    is(
+      await runPython(`findUiaByDomId(doc, "button").CurrentAriaRole`),
+      "button",
+      "button has correct AriaRole"
+    );
+    is(
+      await runPython(`findUiaByDomId(doc, "main").CurrentAriaRole`),
+      "main",
+      "main has correct AriaRole"
+    );
+    is(
+      await runPython(`findUiaByDomId(doc, "unknown").CurrentAriaRole`),
+      "unknown",
+      "unknown has correct AriaRole"
+    );
+    // The IA2 -> UIA proxy doesn't compute ARIA roles.
+    if (gIsUiaEnabled) {
+      is(
+        await runPython(
+          `findUiaByDomId(doc, "computedButton").CurrentAriaRole`
+        ),
+        "button",
+        "computedButton has correct AriaRole"
+      );
+      is(
+        await runPython(`findUiaByDomId(doc, "computedMain").CurrentAriaRole`),
+        "main",
+        "computedMain has correct AriaRole"
+      );
+      is(
+        await runPython(
+          `findUiaByDomId(doc, "computedHeading").CurrentAriaRole`
+        ),
+        "heading",
+        "computedHeading has correct AriaRole"
+      );
+      is(
+        await runPython(`findUiaByDomId(doc, "generic").CurrentAriaRole`),
+        "generic",
+        "generic has correct AriaRole"
+      );
+    }
+  }
+);
+
+/**
+ * Test the LocalizedControlType property. We don't support this ourselves, but
+ * the system provides it based on ControlType and AriaRole.
+ */
+addUiaTask(
+  `
+<button id="button">button</button>
+<h1 id="h1">h1</h1>
+<main id="main">main</main>
+  `,
+  async function testLocalizedControlType() {
+    await definePyVar("doc", `getDocUia()`);
+    is(
+      await runPython(
+        `findUiaByDomId(doc, "button").CurrentLocalizedControlType`
+      ),
+      "button",
+      "button has correct LocalizedControlType"
+    );
+    // The IA2 -> UIA proxy doesn't compute ARIA roles, so it can't compute the
+    // correct LocalizedControlType for these either.
+    if (gIsUiaEnabled) {
+      is(
+        await runPython(
+          `findUiaByDomId(doc, "h1").CurrentLocalizedControlType`
+        ),
+        "heading",
+        "h1 has correct LocalizedControlType"
+      );
+      is(
+        await runPython(
+          `findUiaByDomId(doc, "main").CurrentLocalizedControlType`
+        ),
+        "main",
+        "main has correct LocalizedControlType"
+      );
+    }
+  }
+);
+
+/**
+ * Test the LandmarkType property.
+ */
+addUiaTask(
+  `
+<div id="main" role="main">main</div>
+<main id="htmlMain">htmlMain</main>
+<div id="banner" role="banner">banner</div>
+<header id="header">header</header>
+<div id="region" role="region" aria-label="region">region</div>
+<div id="unnamedRegion" role="region">unnamedRegion</div>
+<main id="mainBanner" role="banner">mainBanner</main>
+<div id="none">none</div>
+  `,
+  async function testLandmarkType() {
+    await definePyVar("doc", `getDocUia()`);
+    is(
+      await runPython(`findUiaByDomId(doc, "main").CurrentLandmarkType`),
+      UIA_MainLandmarkTypeId,
+      "main has correct LandmarkType"
+    );
+    is(
+      await runPython(`findUiaByDomId(doc, "htmlMain").CurrentLandmarkType`),
+      UIA_MainLandmarkTypeId,
+      "htmlMain has correct LandmarkType"
+    );
+    is(
+      await runPython(`findUiaByDomId(doc, "banner").CurrentLandmarkType`),
+      UIA_CustomLandmarkTypeId,
+      "banner has correct LandmarkType"
+    );
+    is(
+      await runPython(`findUiaByDomId(doc, "header").CurrentLandmarkType`),
+      UIA_CustomLandmarkTypeId,
+      "header has correct LandmarkType"
+    );
+    is(
+      await runPython(`findUiaByDomId(doc, "region").CurrentLandmarkType`),
+      UIA_CustomLandmarkTypeId,
+      "region has correct LandmarkType"
+    );
+    is(
+      await runPython(
+        `findUiaByDomId(doc, "unnamedRegion").CurrentLandmarkType`
+      ),
+      0,
+      "unnamedRegion has correct LandmarkType"
+    );
+    // ARIA role takes precedence.
+    is(
+      await runPython(`findUiaByDomId(doc, "mainBanner").CurrentLandmarkType`),
+      UIA_CustomLandmarkTypeId,
+      "mainBanner has correct LandmarkType"
+    );
+    is(
+      await runPython(`findUiaByDomId(doc, "none").CurrentLandmarkType`),
+      0,
+      "none has correct LandmarkType"
+    );
+  }
+);
+
+/**
+ * Test the LocalizedLandmarkType property.
+ */
+addUiaTask(
+  `
+<div id="main" role="main">main</div>
+<div id="contentinfo" role="contentinfo">contentinfo</div>
+<div id="region" role="region" aria-label="region">region</div>
+<div id="unnamedRegion" role="region">unnamedRegion</div>
+<main id="mainBanner" role="banner">mainBanner</main>
+<div id="none">none</div>
+  `,
+  async function testLocalizedLandmarkType() {
+    await definePyVar("doc", `getDocUia()`);
+    // Provided by the system.
+    is(
+      await runPython(
+        `findUiaByDomId(doc, "main").CurrentLocalizedLandmarkType`
+      ),
+      "main",
+      "main has correct LocalizedLandmarkType"
+    );
+    // The IA2 -> UIA proxy doesn't follow the Core AAM spec for this role.
+    if (gIsUiaEnabled) {
+      // Provided by us.
+      is(
+        await runPython(
+          `findUiaByDomId(doc, "contentinfo").CurrentLocalizedLandmarkType`
+        ),
+        "content information",
+        "contentinfo has correct LocalizedLandmarkType"
+      );
+    }
+    is(
+      await runPython(
+        `findUiaByDomId(doc, "region").CurrentLocalizedLandmarkType`
+      ),
+      "region",
+      "region has correct LocalizedLandmarkType"
+    );
+    // Invalid landmark.
+    is(
+      await runPython(
+        `findUiaByDomId(doc, "unnamedRegion").CurrentLocalizedLandmarkType`
+      ),
+      "",
+      "unnamedRegion has correct LocalizedLandmarkType"
+    );
+    // ARIA role takes precedence.
+    is(
+      await runPython(
+        `findUiaByDomId(doc, "mainBanner").CurrentLocalizedLandmarkType`
+      ),
+      "banner",
+      "mainBanner has correct LocalizedLandmarkType"
+    );
+    is(
+      await runPython(
+        `findUiaByDomId(doc, "none").CurrentLocalizedLandmarkType`
+      ),
+      "",
+      "none has correct LocalizedLandmarkType"
+    );
+  }
+);
diff --git a/accessible/tests/browser/windows/uia/browser_gridPatterns.js b/accessible/tests/browser/windows/uia/browser_gridPatterns.js
new file mode 100644
index 0000000000..24c80a6340
--- /dev/null
+++ b/accessible/tests/browser/windows/uia/browser_gridPatterns.js
@@ -0,0 +1,161 @@
+/* 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/. */
+
+"use strict";
+
+/* eslint-disable camelcase */
+const RowOrColumnMajor_RowMajor = 0;
+/* eslint-enable camelcase */
+
+const SNIPPET = `
+<table id="table">
+  <tr><th id="a">a</th><th id="b">b</th><th id="c">c</th></tr>
+  <tr><th id="dg" rowspan="2">dg</th><td id="ef" colspan="2" headers="b c">ef</td></tr>
+  <tr><th id="h">h</th><td id="i" headers="dg h">i</td></tr>
+  <tr><td id="jkl" colspan="3" headers="a b c">jkl</td></tr>
+</table>
+<button id="button">button</button>
+`;
+
+async function testGridGetItem(row, col, cellId) {
+  is(
+    await runPython(`pattern.GetItem(${row}, ${col}).CurrentAutomationId`),
+    cellId,
+    `GetItem with row ${row} and col ${col} returned ${cellId}`
+  );
+}
+
+async function testGridItemProps(id, row, col, rowSpan, colSpan, gridId) {
+  await assignPyVarToUiaWithId(id);
+  await definePyVar("pattern", `getUiaPattern(${id}, "GridItem")`);
+  ok(await runPython(`bool(pattern)`), `${id} has GridItem pattern`);
+  is(await runPython(`pattern.CurrentRow`), row, `${id} has correct Row`);
+  is(await runPython(`pattern.CurrentColumn`), col, `${id} has correct Column`);
+  is(
+    await runPython(`pattern.CurrentRowSpan`),
+    rowSpan,
+    `${id} has correct RowSpan`
+  );
+  is(
+    await runPython(`pattern.CurrentColumnSpan`),
+    colSpan,
+    `${id} has correct ColumnSpan`
+  );
+  is(
+    await runPython(`pattern.CurrentContainingGrid.CurrentAutomationId`),
+    gridId,
+    `${id} ContainingGridItem is ${gridId}`
+  );
+}
+
+async function testTableItemProps(id, rowHeaders, colHeaders) {
+  await assignPyVarToUiaWithId(id);
+  await definePyVar("pattern", `getUiaPattern(${id}, "TableItem")`);
+  ok(await runPython(`bool(pattern)`), `${id} has TableItem pattern`);
+  await isUiaElementArray(
+    `pattern.GetCurrentRowHeaderItems()`,
+    rowHeaders,
+    `${id} has correct RowHeaderItems`
+  );
+  await isUiaElementArray(
+    `pattern.GetCurrentColumnHeaderItems()`,
+    colHeaders,
+    `${id} has correct ColumnHeaderItems`
+  );
+}
+
+/**
+ * Test the Grid pattern.
+ */
+addUiaTask(SNIPPET, async function testGrid() {
+  await definePyVar("doc", `getDocUia()`);
+  await assignPyVarToUiaWithId("table");
+  await definePyVar("pattern", `getUiaPattern(table, "Grid")`);
+  ok(await runPython(`bool(pattern)`), "table has Grid pattern");
+  is(
+    await runPython(`pattern.CurrentRowCount`),
+    4,
+    "table has correct RowCount"
+  );
+  is(
+    await runPython(`pattern.CurrentColumnCount`),
+    3,
+    "table has correct ColumnCount"
+  );
+  await testGridGetItem(0, 0, "a");
+  await testGridGetItem(0, 1, "b");
+  await testGridGetItem(0, 2, "c");
+  await testGridGetItem(1, 0, "dg");
+  await testGridGetItem(1, 1, "ef");
+  await testGridGetItem(1, 2, "ef");
+  await testGridGetItem(2, 0, "dg");
+  await testGridGetItem(2, 1, "h");
+  await testGridGetItem(2, 2, "i");
+
+  await testPatternAbsent("button", "Grid");
+});
+
+/**
+ * Test the GridItem pattern.
+ */
+addUiaTask(SNIPPET, async function testGridItem() {
+  await definePyVar("doc", `getDocUia()`);
+  await testGridItemProps("a", 0, 0, 1, 1, "table");
+  await testGridItemProps("b", 0, 1, 1, 1, "table");
+  await testGridItemProps("c", 0, 2, 1, 1, "table");
+  await testGridItemProps("dg", 1, 0, 2, 1, "table");
+  await testGridItemProps("ef", 1, 1, 1, 2, "table");
+  await testGridItemProps("jkl", 3, 0, 1, 3, "table");
+
+  await testPatternAbsent("button", "GridItem");
+});
+
+/**
+ * Test the Table pattern.
+ */
+addUiaTask(
+  SNIPPET,
+  async function testTable() {
+    await definePyVar("doc", `getDocUia()`);
+    await assignPyVarToUiaWithId("table");
+    await definePyVar("pattern", `getUiaPattern(table, "Table")`);
+    ok(await runPython(`bool(pattern)`), "table has Table pattern");
+    await isUiaElementArray(
+      `pattern.GetCurrentRowHeaders()`,
+      ["dg", "h"],
+      "table has correct RowHeaders"
+    );
+    await isUiaElementArray(
+      `pattern.GetCurrentColumnHeaders()`,
+      ["a", "b", "c"],
+      "table has correct ColumnHeaders"
+    );
+    is(
+      await runPython(`pattern.CurrentRowOrColumnMajor`),
+      RowOrColumnMajor_RowMajor,
+      "table has correct RowOrColumnMajor"
+    );
+
+    await testPatternAbsent("button", "Table");
+  },
+  // The IA2 -> UIA proxy doesn't support the Row/ColumnHeaders properties.
+  { uiaEnabled: true, uiaDisabled: false }
+);
+
+/**
+ * Test the TableItem pattern.
+ */
+addUiaTask(SNIPPET, async function testTableItem() {
+  await definePyVar("doc", `getDocUia()`);
+  await testTableItemProps("a", [], []);
+  await testTableItemProps("b", [], []);
+  await testTableItemProps("c", [], []);
+  await testTableItemProps("dg", [], ["a"]);
+  await testTableItemProps("ef", ["dg"], ["b", "c"]);
+  await testTableItemProps("h", ["dg"], ["b"]);
+  await testTableItemProps("i", ["dg", "h"], ["c"]);
+  await testTableItemProps("jkl", [], ["a", "b", "c"]);
+
+  await testPatternAbsent("button", "TableItem");
+});
diff --git a/accessible/tests/browser/windows/uia/browser_relationProps.js b/accessible/tests/browser/windows/uia/browser_relationProps.js
new file mode 100644
index 0000000000..ff4059f99e
--- /dev/null
+++ b/accessible/tests/browser/windows/uia/browser_relationProps.js
@@ -0,0 +1,143 @@
+/* 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/. */
+
+"use strict";
+
+function testUiaRelationArray(id, prop, targets) {
+  return isUiaElementArray(
+    `findUiaByDomId(doc, "${id}").Current${prop}`,
+    targets,
+    `${id} has correct ${prop} targets`
+  );
+}
+
+/**
+ * Test the ControllerFor property.
+ */
+addUiaTask(
+  `
+<input id="controls" aria-controls="t1 t2">
+<input id="error" aria-errormessage="t3 t4" aria-invalid="true">
+<input id="controlsError" aria-controls="t1 t2" aria-errormessage="t3 t4" aria-invalid="true">
+<div id="t1">t1</div>
+<div id="t2">t2</div>
+<div id="t3">t3</div>
+<div id="t4">t4</div>
+<button id="none">none</button>
+  `,
+  async function testControllerFor() {
+    await definePyVar("doc", `getDocUia()`);
+    await testUiaRelationArray("controls", "ControllerFor", ["t1", "t2"]);
+    // The IA2 -> UIA proxy doesn't support IA2_RELATION_ERROR.
+    if (gIsUiaEnabled) {
+      await testUiaRelationArray("error", "ControllerFor", ["t3", "t4"]);
+      await testUiaRelationArray("controlsError", "ControllerFor", [
+        "t1",
+        "t2",
+        "t3",
+        "t4",
+      ]);
+    }
+    await testUiaRelationArray("none", "ControllerFor", []);
+  }
+);
+
+/**
+ * Test the DescribedBy property.
+ */
+addUiaTask(
+  `
+<input id="describedby" aria-describedby="t1 t2">
+<input id="details" aria-details="t3 t4">
+<input id="describedbyDetails" aria-describedby="t1 t2" aria-details="t3 t4" aria-invalid="true">
+<div id="t1">t1</div>
+<div id="t2">t2</div>
+<div id="t3">t3</div>
+<div id="t4">t4</div>
+<button id="none">none</button>
+  `,
+  async function testDescribedBy() {
+    await definePyVar("doc", `getDocUia()`);
+    await testUiaRelationArray("describedby", "DescribedBy", ["t1", "t2"]);
+    // The IA2 -> UIA proxy doesn't support IA2_RELATION_DETAILS.
+    if (gIsUiaEnabled) {
+      await testUiaRelationArray("details", "DescribedBy", ["t3", "t4"]);
+      await testUiaRelationArray("describedbyDetails", "DescribedBy", [
+        "t1",
+        "t2",
+        "t3",
+        "t4",
+      ]);
+    }
+    await testUiaRelationArray("none", "DescribedBy", []);
+  }
+);
+
+/**
+ * Test the FlowsFrom and FlowsTo properties.
+ */
+addUiaTask(
+  `
+<div id="t1" aria-flowto="t2">t1</div>
+<div id="t2">t2</div>
+<button id="none">none</button>
+  `,
+  async function testFlows() {
+    await definePyVar("doc", `getDocUia()`);
+    await testUiaRelationArray("t1", "FlowsTo", ["t2"]);
+    await testUiaRelationArray("t2", "FlowsFrom", ["t1"]);
+    await testUiaRelationArray("none", "FlowsFrom", []);
+    await testUiaRelationArray("none", "FlowsTo", []);
+  }
+);
+
+/**
+ * Test the LabeledBy property.
+ */
+addUiaTask(
+  `
+<label id="label">label</label>
+<input id="input" aria-labelledby="label">
+<label id="wrappingLabel">
+  <input id="wrappedInput" value="wrappedInput">
+  <p id="wrappingLabelP">wrappingLabel</p>
+</label>
+<button id="button" aria-labelledby="label">content</button>
+<button id="noLabel">noLabel</button>
+  `,
+  async function testLabeledBy() {
+    await definePyVar("doc", `getDocUia()`);
+    // input's LabeledBy should be label's text leaf.
+    let result = await runPython(`
+      input = findUiaByDomId(doc, "input")
+      label = findUiaByDomId(doc, "label")
+      labelLeaf = uiaClient.RawViewWalker.GetFirstChildElement(label)
+      return uiaClient.CompareElements(input.CurrentLabeledBy, labelLeaf)
+    `);
+    ok(result, "input has correct LabeledBy");
+    // wrappedInput's LabeledBy should be wrappingLabelP's text leaf.
+    result = await runPython(`
+      wrappedInput = findUiaByDomId(doc, "wrappedInput")
+      wrappingLabelP = findUiaByDomId(doc, "wrappingLabelP")
+      wrappingLabelLeaf = uiaClient.RawViewWalker.GetFirstChildElement(wrappingLabelP)
+      return uiaClient.CompareElements(wrappedInput.CurrentLabeledBy, wrappingLabelLeaf)
+    `);
+    ok(result, "wrappedInput has correct LabeledBy");
+    // button has aria-labelledby, but UIA prohibits LabeledBy on buttons.
+    ok(
+      !(await runPython(
+        `bool(findUiaByDomId(doc, "button").CurrentLabeledBy)`
+      )),
+      "button has no LabeledBy"
+    );
+    ok(
+      !(await runPython(
+        `bool(findUiaByDomId(doc, "noLabel").CurrentLabeledBy)`
+      )),
+      "noLabel has no LabeledBy"
+    );
+  },
+  // The IA2 -> UIA proxy doesn't expose LabeledBy properly.
+  { uiaEnabled: true, uiaDisabled: false }
+);
diff --git a/accessible/tests/browser/windows/uia/browser_selectionPatterns.js b/accessible/tests/browser/windows/uia/browser_selectionPatterns.js
new file mode 100644
index 0000000000..a1f70b886a
--- /dev/null
+++ b/accessible/tests/browser/windows/uia/browser_selectionPatterns.js
@@ -0,0 +1,226 @@
+/* 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/. */
+
+"use strict";
+
+const SNIPPET = `
+<select id="selectList" size="2">
+  <option id="sl1" selected>sl1</option>
+  <option id="sl2">sl2</option>
+</select>
+<select id="selectRequired" size="2" required>
+  <option id="sr1">sr1</option>
+</select>
+<select id="selectMulti" size="2" multiple>
+  <option id="sm1" selected>sm1</option>
+  <option id="sm2">sm2</option>
+  <option id="sm3" selected>sm3</option>
+  <option id="sm4">sm4</option>
+  <option id="sm5">sm5</option>
+  <option id="sm6">sm6</option>
+</select>
+<select id="selectCombo" size="1">
+  <option>sc1</option>
+</select>
+<div id="ariaListbox" role="listbox">
+  <div id="al1" role="option" aria-selected="true">al1</div>
+  <div id="al2" role="option">al2</div>
+</div>
+<div id="tablist" role="tablist">
+  <div id="t1" role="tab">t1</div>
+  <div id="t2" role="tab" aria-selected="true">t2</div>
+</div>
+<table id="grid" role="grid" aria-multiselectable="true">
+  <tr>
+    <td id="g1">g1</td>
+    <td id="g2" role="gridcell" aria-selected="true">g2</td>
+  </tr>
+  <tr>
+    <td id="g3">g3</td>
+    <td id="g4" role="gridcell" aria-selected="true">g4</td>
+  </tr>
+</table>
+<div id="radiogroup" role="radiogroup">
+  <label><input id="r1" type="radio" name="r" checked>r1</label>
+  <label><input id="r2" type="radio" name="r">r2</label>
+</div>
+<div id="menu" role="menu">
+  <div id="m1" role="menuitem">m1</div>
+  <div id="m2" role="menuitemradio">m2</div>
+  <div id="m3" role="menuitemradio" aria-checked="true">m3</div>
+</div>
+<button id="button">button</button>
+`;
+
+async function testSelectionProps(id, selection, multiple, required) {
+  await assignPyVarToUiaWithId(id);
+  await definePyVar("pattern", `getUiaPattern(${id}, "Selection")`);
+  ok(await runPython(`bool(pattern)`), `${id} has Selection pattern`);
+  await isUiaElementArray(
+    `pattern.GetCurrentSelection()`,
+    selection,
+    `${id} has correct Selection`
+  );
+  is(
+    !!(await runPython(`pattern.CurrentCanSelectMultiple`)),
+    multiple,
+    `${id} has correct CanSelectMultiple`
+  );
+  // The IA2 -> UIA proxy doesn't reflect the required state correctly.
+  if (gIsUiaEnabled) {
+    is(
+      !!(await runPython(`pattern.CurrentIsSelectionRequired`)),
+      required,
+      `${id} has correct IsSelectionRequired`
+    );
+  }
+}
+
+async function testSelectionItemProps(id, selected, container) {
+  await assignPyVarToUiaWithId(id);
+  await definePyVar("pattern", `getUiaPattern(${id}, "SelectionItem")`);
+  ok(await runPython(`bool(pattern)`), `${id} has SelectionItem pattern`);
+  is(
+    !!(await runPython(`pattern.CurrentIsSelected`)),
+    selected,
+    `${id} has correct IsSelected`
+  );
+  if (container) {
+    is(
+      await runPython(`pattern.CurrentSelectionContainer.CurrentAutomationId`),
+      container,
+      `${id} has correct SelectionContainer`
+    );
+  } else {
+    ok(
+      !(await runPython(`bool(pattern.CurrentSelectionContainer)`)),
+      `${id} has no SelectionContainer`
+    );
+  }
+}
+
+/**
+ * Test the Selection pattern.
+ */
+addUiaTask(SNIPPET, async function testSelection(browser) {
+  await definePyVar("doc", `getDocUia()`);
+  await testSelectionProps("selectList", ["sl1"], false, false);
+  await testSelectionProps("selectRequired", [], false, true);
+
+  await testSelectionProps("selectMulti", ["sm1", "sm3"], true, false);
+  // The Selection pattern only has an event for a complete invalidation of the
+  // container's selection, which only happens when there are too many selection
+  // events. Smaller selection changes fire events in the SelectionItem pattern.
+  info("Changing selectMulti selection");
+  await setUpWaitForUiaEvent("Selection_Invalidated", "selectMulti");
+  await invokeContentTask(browser, [], () => {
+    const multi = content.document.getElementById("selectMulti");
+    multi[0].selected = false;
+    multi[1].selected = true;
+    multi[2].selected = false;
+    multi[3].selected = true;
+    multi[4].selected = true;
+    multi[5].selected = true;
+  });
+  await waitForUiaEvent();
+  ok(true, "select got Invalidated event");
+  await testSelectionProps(
+    "selectMulti",
+    ["sm2", "sm4", "sm5", "sm6"],
+    true,
+    false
+  );
+
+  await testPatternAbsent("selectCombo", "Selection");
+
+  await testSelectionProps("ariaListbox", ["al1"], false, false);
+  await testSelectionProps("tablist", ["t2"], false, false);
+  // The IA2 -> UIA proxy doesn't expose the Selection pattern on grids.
+  if (gIsUiaEnabled) {
+    await testSelectionProps("grid", ["g2", "g4"], true, false);
+  }
+
+  // radio gets the SelectionItem pattern, but radiogroup doesn't get the
+  // Selection pattern for now. Same for menu/menuitemradio.
+  await testPatternAbsent("radiogroup", "Selection");
+  await testPatternAbsent("menu", "Selection");
+
+  await testPatternAbsent("button", "Selection");
+});
+
+/**
+ * Test the SelectionItem pattern.
+ */
+addUiaTask(SNIPPET, async function testSelection() {
+  await definePyVar("doc", `getDocUia()`);
+  await testPatternAbsent("selectList", "SelectionItem");
+  await testSelectionItemProps("sl1", true, "selectList");
+  await testSelectionItemProps("sl2", false, "selectList");
+  info("Calling Select on sl2");
+  await setUpWaitForUiaEvent("SelectionItem_ElementSelected", "sl2");
+  await runPython(`pattern.Select()`);
+  await waitForUiaEvent();
+  ok(true, "sl2 got ElementSelected event");
+  await testSelectionItemProps("sl1", false, "selectList");
+  await testSelectionItemProps("sl2", true, "selectList");
+
+  await testSelectionItemProps("sr1", false, "selectRequired");
+
+  await testSelectionItemProps("sm1", true, "selectMulti");
+  await testSelectionItemProps("sm2", false, "selectMulti");
+  info("Calling AddToSelection on sm2");
+  await setUpWaitForUiaEvent("SelectionItem_ElementAddedToSelection", "sm2");
+  await runPython(`pattern.AddToSelection()`);
+  await waitForUiaEvent();
+  ok(true, "sm2 got ElementAddedToSelection event");
+  await testSelectionItemProps("sm2", true, "selectMulti");
+  await testSelectionItemProps("sm3", true, "selectMulti");
+  info("Calling RemoveFromSelection on sm3");
+  await setUpWaitForUiaEvent(
+    "SelectionItem_ElementRemovedFromSelection",
+    "sm3"
+  );
+  await runPython(`pattern.RemoveFromSelection()`);
+  await waitForUiaEvent();
+  ok(true, "sm3 got ElementRemovedFromSelection event");
+  await testSelectionItemProps("sm3", false, "selectMulti");
+
+  await testSelectionItemProps("t1", false, "tablist");
+  await testSelectionItemProps("t2", true, "tablist");
+
+  // The IA2 -> UIA proxy doesn't expose the SelectionItem pattern on grid
+  // cells.
+  if (gIsUiaEnabled) {
+    await testSelectionItemProps("g1", false, "grid");
+    await testSelectionItemProps("g2", true, "grid");
+  }
+
+  await testSelectionItemProps("r1", true, null);
+  await testSelectionItemProps("r2", false, null);
+  // The IA2 -> UIA proxy doesn't fire correct events for radio buttons.
+  if (gIsUiaEnabled) {
+    info("Calling Select on r2");
+    await setUpWaitForUiaEvent("SelectionItem_ElementSelected", "r2");
+    await runPython(`pattern.Select()`);
+    await waitForUiaEvent();
+    ok(true, "r2 got ElementSelected event");
+    await testSelectionItemProps("r1", false, null);
+    await testSelectionItemProps("r2", true, null);
+    info("Calling RemoveFromSelection on r2");
+    await testPythonRaises(
+      `pattern.RemoveFromSelection()`,
+      "RemoveFromSelection failed on r2"
+    );
+  }
+
+  await testPatternAbsent("m1", "SelectionItem");
+  // The IA2 -> UIA proxy doesn't expose the SelectionItem pattern for radio
+  // menu items.
+  if (gIsUiaEnabled) {
+    await testSelectionItemProps("m2", false, null);
+    await testSelectionItemProps("m3", true, null);
+  }
+
+  await testPatternAbsent("button", "SelectionItem");
+});
diff --git a/accessible/tests/browser/windows/uia/browser_simplePatterns.js b/accessible/tests/browser/windows/uia/browser_simplePatterns.js
index f464db0e13..484d217af2 100644
--- a/accessible/tests/browser/windows/uia/browser_simplePatterns.js
+++ b/accessible/tests/browser/windows/uia/browser_simplePatterns.js
@@ -27,6 +27,7 @@ addUiaTask(
 <button id="button">button</button>
 <p id="p">p</p>
 <input id="checkbox" type="checkbox">
+<input id="radio" type="radio">
   `,
   async function testInvoke() {
     await definePyVar("doc", `getDocUia()`);
@@ -54,6 +55,8 @@ addUiaTask(
       // Check boxes expose the Toggle pattern, so they should not expose the
       // Invoke pattern.
       await testPatternAbsent("checkbox", "Invoke");
+      // Ditto for radio buttons.
+      await testPatternAbsent("radio", "Invoke");
     }
   }
 );
@@ -317,6 +320,7 @@ addUiaTask(
     await setUpWaitForUiaPropEvent("ValueValue", "text");
     await runPython(`pattern.SetValue("after")`);
     await waitForUiaEvent();
+    ok(true, "Got ValueValue prop change event on text");
     is(
       await runPython(`pattern.CurrentValue`),
       "after",
@@ -434,6 +438,7 @@ addUiaTask(
     await setUpWaitForUiaPropEvent("ValueValue", "ariaTextbox");
     await runPython(`pattern.SetValue("after")`);
     await waitForUiaEvent();
+    ok(true, "Got ValueValue prop change event on ariaTextbox");
     is(
       await runPython(`pattern.CurrentValue`),
       "after",
@@ -443,3 +448,95 @@ addUiaTask(
     await testPatternAbsent("button", "Value");
   }
 );
+
+async function testRangeValueProps(id, ro, val, min, max, small, large) {
+  await assignPyVarToUiaWithId(id);
+  await definePyVar("pattern", `getUiaPattern(${id}, "RangeValue")`);
+  ok(await runPython(`bool(pattern)`), `${id} has RangeValue pattern`);
+  is(
+    !!(await runPython(`pattern.CurrentIsReadOnly`)),
+    ro,
+    `${id} has IsReadOnly ${ro}`
+  );
+  is(await runPython(`pattern.CurrentValue`), val, `${id} has correct Value`);
+  is(
+    await runPython(`pattern.CurrentMinimum`),
+    min,
+    `${id} has correct Minimum`
+  );
+  is(
+    await runPython(`pattern.CurrentMaximum`),
+    max,
+    `${id} has correct Maximum`
+  );
+  // IA2 doesn't support small/large change, so the IA2 -> UIA proxy can't
+  // either.
+  if (gIsUiaEnabled) {
+    is(
+      await runPython(`pattern.CurrentSmallChange`),
+      small,
+      `${id} has correct SmallChange`
+    );
+    is(
+      await runPython(`pattern.CurrentLargeChange`),
+      large,
+      `${id} has correct LargeChange`
+    );
+  }
+}
+
+/**
+ * Test the RangeValue pattern.
+ */
+addUiaTask(
+  `
+<input id="range" type="range">
+<input id="rangeBig" type="range" max="1000">
+<progress id="progress" value="0.5"></progress>
+<input id="numberRo" type="number" min="0" max="10" value="5" readonly>
+<div id="ariaSlider" role="slider">slider</div>
+<button id="button">button</button>
+  `,
+  async function testRangeValue(browser) {
+    await definePyVar("doc", `getDocUia()`);
+    await testRangeValueProps("range", false, 50, 0, 100, 1, 10);
+    info("SetValue on range");
+    await setUpWaitForUiaPropEvent("RangeValueValue", "range");
+    await runPython(`pattern.SetValue(20)`);
+    await waitForUiaEvent();
+    ok(true, "Got RangeValueValue prop change event on range");
+    is(await runPython(`pattern.CurrentValue`), 20, "range has correct Value");
+
+    await testRangeValueProps("rangeBig", false, 500, 0, 1000, 1, 100);
+
+    // Gecko a11y doesn't expose progress bars as read only, but it probably
+    // should.
+    await testRangeValueProps("progress", false, 0.5, 0, 1, 0, 0.1);
+    info("Calling SetValue on progress");
+    await testPythonRaises(
+      `pattern.SetValue(0.6)`,
+      "SetValue on progress failed"
+    );
+
+    await testRangeValueProps("numberRo", true, 5, 0, 10, 1, 1);
+    info("Calling SetValue on numberRo");
+    await testPythonRaises(
+      `pattern.SetValue(6)`,
+      "SetValue on numberRo failed"
+    );
+
+    await testRangeValueProps("ariaSlider", false, 50, 0, 100, null, null);
+    info("Setting aria-valuenow on ariaSlider");
+    await setUpWaitForUiaPropEvent("RangeValueValue", "ariaSlider");
+    await invokeSetAttribute(browser, "ariaSlider", "aria-valuenow", "60");
+    await waitForUiaEvent();
+    ok(true, "Got RangeValueValue prop change event on ariaSlider");
+    is(
+      await runPython(`pattern.CurrentValue`),
+      60,
+      "ariaSlider has correct Value"
+    );
+
+    await testPatternAbsent("button", "RangeValue");
+  }
+);
diff --git a/accessible/tests/browser/windows/uia/head.js b/accessible/tests/browser/windows/uia/head.js
index 5b453ce6fe..217b8cb844 100644
--- a/accessible/tests/browser/windows/uia/head.js
+++ b/accessible/tests/browser/windows/uia/head.js
@@ -4,7 +4,7 @@
 
 "use strict";
 
-/* exported gIsUiaEnabled, addUiaTask, definePyVar, assignPyVarToUiaWithId, setUpWaitForUiaEvent, setUpWaitForUiaPropEvent, waitForUiaEvent, testPatternAbsent, testPythonRaises */
+/* exported gIsUiaEnabled, addUiaTask, definePyVar, assignPyVarToUiaWithId, setUpWaitForUiaEvent, setUpWaitForUiaPropEvent, waitForUiaEvent, testPatternAbsent, testPythonRaises, isUiaElementArray */
 
 // Load the shared-head file first.
 Services.scriptloader.loadSubScript(
@@ -126,3 +126,15 @@ async function testPythonRaises(expression, message) {
   }
   ok(failed, message);
 }
+
+/**
+ * Verify that an array of UIA elements contains (only) elements with the given
+ * DOM ids.
+ */
+async function isUiaElementArray(pyExpr, ids, message) {
+  const result = await runPython(`
+    uias = (${pyExpr})
+    return [uias.GetElement(i).CurrentAutomationId for i in range(uias.Length)]
+  `);
+  SimpleTest.isDeeply(result, ids, message);
+}
diff --git a/accessible/tests/mochitest/attributes.js b/accessible/tests/mochitest/attributes.js
index ebb5a54b85..65afebd83a 100644
--- a/accessible/tests/mochitest/attributes.js
+++ b/accessible/tests/mochitest/attributes.js
@@ -295,13 +295,10 @@ const kBoldFontWeight = function equalsToBold(aWeight) {
   return aWeight > 400;
 };
 
-let isNNT = SpecialPowers.getBoolPref("widget.non-native-theme.enabled");
 // The pt font size of the input element can vary by Linux distro.
 const kInputFontSize =
-  WIN || (MAC && isNNT)
+  WIN || MAC
     ? "10pt"
-    : MAC
-    ? "8pt"
     : function () {
         return true;
       };
diff --git a/accessible/tests/mochitest/role/test_dpub_aria.html b/accessible/tests/mochitest/role/test_dpub_aria.html
index 621c86a59b..8294669caf 100644
--- a/accessible/tests/mochitest/role/test_dpub_aria.html
+++ b/accessible/tests/mochitest/role/test_dpub_aria.html
@@ -36,7 +36,7 @@
       testRole("doc-epigraph", ROLE_SECTION);
       testRole("doc-epilogue", ROLE_LANDMARK);
       testRole("doc-errata", ROLE_LANDMARK);
-      testRole("doc-example", ROLE_SECTION);
+      testRole("doc-example", ROLE_FIGURE);
       testRole("doc-footnote", ROLE_FOOTNOTE);
       testRole("doc-foreword", ROLE_LANDMARK);
       testRole("doc-glossary", ROLE_LANDMARK);
@@ -46,6 +46,8 @@
       testRole("doc-noteref", ROLE_LINK);
       testRole("doc-notice", ROLE_NOTE);
       testRole("doc-pagebreak", ROLE_SEPARATOR);
+      testRole("doc-pagefooter", ROLE_SECTION);
+      testRole("doc-pageheader", ROLE_SECTION);
       testRole("doc-pagelist", ROLE_NAVIGATION);
       testRole("doc-part", ROLE_LANDMARK);
       testRole("doc-preface", ROLE_LANDMARK);
@@ -101,6 +103,8 @@
   <div id="doc-noteref" role="doc-noteref">noteref</div>
   <div id="doc-notice" role="doc-notice">notice</div>
   <div id="doc-pagebreak" role="doc-pagebreak">pagebreak</div>
+  <div id="doc-pagefooter" role="doc-pagefooter">pagefooter</div>
+  <div id="doc-pageheader" role="doc-pageheader">pageheader</div>
   <div id="doc-pagelist" role="doc-pagelist">pagelist</div>
   <div id="doc-part" role="doc-part">part</div>
   <div id="doc-preface" role="doc-preface">preface</div>
diff --git a/accessible/windows/ia2/ia2AccessibleTable.cpp b/accessible/windows/ia2/ia2AccessibleTable.cpp
index 50bdc79967..9ce94e8348 100644
--- a/accessible/windows/ia2/ia2AccessibleTable.cpp
+++ b/accessible/windows/ia2/ia2AccessibleTable.cpp
@@ -21,7 +21,7 @@
 using namespace mozilla::a11y;
 
 TableAccessible* ia2AccessibleTable::TableAcc() {
-  Accessible* acc = Acc();
+  Accessible* acc = MsaaAccessible::Acc();
   return acc ? acc->AsTable() : nullptr;
 }
 
@@ -46,6 +46,18 @@ ia2AccessibleTable::QueryInterface(REFIID iid, void** ppv) {
     return S_OK;
   }
 
+  if (IID_IGridProvider == iid) {
+    *ppv = static_cast<IGridProvider*>(this);
+    (reinterpret_cast<IUnknown*>(*ppv))->AddRef();
+    return S_OK;
+  }
+
+  if (IID_ITableProvider == iid) {
+    *ppv = static_cast<ITableProvider*>(this);
+    (reinterpret_cast<IUnknown*>(*ppv))->AddRef();
+    return S_OK;
+  }
+
   return ia2AccessibleHypertext::QueryInterface(iid, ppv);
 }
 
diff --git a/accessible/windows/ia2/ia2AccessibleTable.h b/accessible/windows/ia2/ia2AccessibleTable.h
index 622187c379..e8479b1733 100644
--- a/accessible/windows/ia2/ia2AccessibleTable.h
+++ b/accessible/windows/ia2/ia2AccessibleTable.h
@@ -12,6 +12,7 @@
 #include "AccessibleTable2.h"
 #include "ia2AccessibleHypertext.h"
 #include "IUnknownImpl.h"
+#include "UiaGrid.h"
 
 namespace mozilla {
 namespace a11y {
@@ -20,6 +21,7 @@ class TableAccessible;
 
 class ia2AccessibleTable : public IAccessibleTable,
                            public IAccessibleTable2,
+                           public UiaGrid,
                            public ia2AccessibleHypertext {
  public:
   // IUnknown
diff --git a/accessible/windows/ia2/ia2AccessibleTableCell.cpp b/accessible/windows/ia2/ia2AccessibleTableCell.cpp
index 0204983a08..c8e98d6a2f 100644
--- a/accessible/windows/ia2/ia2AccessibleTableCell.cpp
+++ b/accessible/windows/ia2/ia2AccessibleTableCell.cpp
@@ -27,6 +27,8 @@ TableCellAccessible* ia2AccessibleTableCell::CellAcc() {
 // IUnknown
 IMPL_IUNKNOWN_QUERY_HEAD(ia2AccessibleTableCell)
 IMPL_IUNKNOWN_QUERY_IFACE(IAccessibleTableCell)
+IMPL_IUNKNOWN_QUERY_IFACE(IGridItemProvider)
+IMPL_IUNKNOWN_QUERY_IFACE(ITableItemProvider)
 IMPL_IUNKNOWN_QUERY_TAIL_INHERITED(ia2AccessibleHypertext)
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/accessible/windows/ia2/ia2AccessibleTableCell.h b/accessible/windows/ia2/ia2AccessibleTableCell.h
index 04e978cb96..6925cd7b17 100644
--- a/accessible/windows/ia2/ia2AccessibleTableCell.h
+++ b/accessible/windows/ia2/ia2AccessibleTableCell.h
@@ -11,12 +11,14 @@
 #include "AccessibleTableCell.h"
 #include "ia2AccessibleHypertext.h"
 #include "IUnknownImpl.h"
+#include "UiaGridItem.h"
 
 namespace mozilla {
 namespace a11y {
 class TableCellAccessible;
 
 class ia2AccessibleTableCell : public IAccessibleTableCell,
+                               public UiaGridItem,
                                public ia2AccessibleHypertext {
  public:
   // IUnknown
diff --git a/accessible/windows/msaa/IUnknownImpl.h b/accessible/windows/msaa/IUnknownImpl.h
index 7935ebedda..757bff44bf 100644
--- a/accessible/windows/msaa/IUnknownImpl.h
+++ b/accessible/windows/msaa/IUnknownImpl.h
@@ -47,31 +47,31 @@ class AutoRefCnt {
 }  // namespace a11y
 }  // namespace mozilla
 
-#define DECL_IUNKNOWN                                               \
- public:                                                            \
-  virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID, void**); \
-  ULONG STDMETHODCALLTYPE AddRef() override {                       \
-    MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");            \
-    ++mRefCnt;                                                      \
-    return mRefCnt;                                                 \
-  }                                                                 \
-  ULONG STDMETHODCALLTYPE Release() override {                      \
-    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                \
-    --mRefCnt;                                                      \
-    if (mRefCnt) return mRefCnt;                                    \
-                                                                    \
-    delete this;                                                    \
-    return 0;                                                       \
-  }                                                                 \
-                                                                    \
- private:                                                           \
-  mozilla::a11y::AutoRefCnt mRefCnt;                                \
-                                                                    \
+#define DECL_IUNKNOWN                                                        \
+ public:                                                                     \
+  virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID, void**) override; \
+  ULONG STDMETHODCALLTYPE AddRef() override {                                \
+    MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");                     \
+    ++mRefCnt;                                                               \
+    return mRefCnt;                                                          \
+  }                                                                          \
+  ULONG STDMETHODCALLTYPE Release() override {                               \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                         \
+    --mRefCnt;                                                               \
+    if (mRefCnt) return mRefCnt;                                             \
+                                                                             \
+    delete this;                                                             \
+    return 0;                                                                \
+  }                                                                          \
+                                                                             \
+ private:                                                                    \
+  mozilla::a11y::AutoRefCnt mRefCnt;                                         \
+                                                                             \
  public:
 
 #define DECL_IUNKNOWN_INHERITED \
  public:                        \
-  virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID, void**);
+  virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID, void**) override;
 
 #define IMPL_IUNKNOWN_QUERY_HEAD(Class)                     \
   STDMETHODIMP                                              \
diff --git a/accessible/windows/msaa/LazyInstantiator.cpp b/accessible/windows/msaa/LazyInstantiator.cpp
index 61814d059a..3ace26d9c0 100644
--- a/accessible/windows/msaa/LazyInstantiator.cpp
+++ b/accessible/windows/msaa/LazyInstantiator.cpp
@@ -12,6 +12,7 @@
 #include "mozilla/a11y/Platform.h"
 #include "mozilla/Assertions.h"
 #include "mozilla/mscom/ProcessRuntime.h"
+#include "mozilla/StaticPrefs_accessibility.h"
 #include "mozilla/UniquePtr.h"
 #include "mozilla/WinHeaderOnlyUtils.h"
 #include "MsaaRootAccessible.h"
@@ -41,9 +42,9 @@ static const wchar_t kLazyInstantiatorProp[] =
 
 Maybe<bool> LazyInstantiator::sShouldBlockUia;
 
-/* static */
-already_AddRefed<IAccessible> LazyInstantiator::GetRootAccessible(HWND aHwnd) {
-  RefPtr<IAccessible> result;
+template <class T>
+already_AddRefed<T> LazyInstantiator::GetRoot(HWND aHwnd) {
+  RefPtr<T> result;
   // At this time we only want to check whether the acc service is running. We
   // don't actually want to create the acc service yet.
   if (!GetAccService()) {
@@ -80,7 +81,7 @@ already_AddRefed<IAccessible> LazyInstantiator::GetRootAccessible(HWND aHwnd) {
   if (!rootAcc->IsRoot()) {
     // rootAcc might represent a popup as opposed to a true root accessible.
     // In that case we just use the regular LocalAccessible::GetNativeInterface.
-    rootAcc->GetNativeInterface(getter_AddRefs(result));
+    result = MsaaAccessible::GetFrom(rootAcc);
     return result.forget();
   }
 
@@ -90,7 +91,7 @@ already_AddRefed<IAccessible> LazyInstantiator::GetRootAccessible(HWND aHwnd) {
   // don't need LazyInstantiator's capabilities anymore (since a11y is already
   // running). We can bypass LazyInstantiator by retrieving the internal
   // unknown (which is not wrapped by the LazyInstantiator) and then querying
-  // that for IID_IAccessible.
+  // that for the interface we want.
   RefPtr<IUnknown> punk(msaaRoot->GetInternalUnknown());
 
   MOZ_ASSERT(punk);
@@ -98,10 +99,24 @@ already_AddRefed<IAccessible> LazyInstantiator::GetRootAccessible(HWND aHwnd) {
     return nullptr;
   }
 
-  punk->QueryInterface(IID_IAccessible, getter_AddRefs(result));
+  punk->QueryInterface(__uuidof(T), getter_AddRefs(result));
   return result.forget();
 }
 
+/* static */
+already_AddRefed<IAccessible> LazyInstantiator::GetRootAccessible(HWND aHwnd) {
+  return GetRoot<IAccessible>(aHwnd);
+}
+
+/* static */
+already_AddRefed<IRawElementProviderSimple> LazyInstantiator::GetRootUia(
+    HWND aHwnd) {
+  if (!StaticPrefs::accessibility_uia_enable()) {
+    return nullptr;
+  }
+  return GetRoot<IRawElementProviderSimple>(aHwnd);
+}
+
 /**
  * When marshaling an interface, COM makes a whole bunch of QueryInterface
  * calls to determine what kind of marshaling the interface supports. We need
@@ -135,7 +150,8 @@ LazyInstantiator::LazyInstantiator(HWND aHwnd)
       mAllowBlindAggregation(false),
       mWeakMsaaRoot(nullptr),
       mWeakAccessible(nullptr),
-      mWeakDispatch(nullptr) {
+      mWeakDispatch(nullptr),
+      mWeakUia(nullptr) {
   MOZ_ASSERT(aHwnd);
   // Assign ourselves as the designated LazyInstantiator for aHwnd
   DebugOnly<BOOL> setPropOk =
@@ -374,9 +390,16 @@ LazyInstantiator::MaybeResolveRoot() {
     if (FAILED(hr)) {
       return hr;
     }
-
     // mWeakAccessible is weak, so don't hold a strong ref
     mWeakAccessible->Release();
+    if (StaticPrefs::accessibility_uia_enable()) {
+      hr = mRealRootUnk->QueryInterface(IID_IRawElementProviderSimple,
+                                        (void**)&mWeakUia);
+      if (FAILED(hr)) {
+        return hr;
+      }
+      mWeakUia->Release();
+    }
 
     // Now that a11y is running, we don't need to remain registered with our
     // HWND anymore.
@@ -401,6 +424,9 @@ IMPL_IUNKNOWN_QUERY_IFACE_AMBIGIOUS(IUnknown, IAccessible)
 IMPL_IUNKNOWN_QUERY_IFACE(IAccessible)
 IMPL_IUNKNOWN_QUERY_IFACE(IDispatch)
 IMPL_IUNKNOWN_QUERY_IFACE(IServiceProvider)
+if (StaticPrefs::accessibility_uia_enable()) {
+  IMPL_IUNKNOWN_QUERY_IFACE(IRawElementProviderSimple)
+}
 // See EnableBlindAggregation for comments.
 if (!mAllowBlindAggregation) {
   return E_NOINTERFACE;
@@ -771,5 +797,45 @@ LazyInstantiator::QueryService(REFGUID aServiceId, REFIID aServiceIid,
   return servProv->QueryService(aServiceId, aServiceIid, aOutInterface);
 }
 
+STDMETHODIMP
+LazyInstantiator::get_ProviderOptions(
+    __RPC__out enum ProviderOptions* aOptions) {
+  // This method is called before a UIA connection is fully established and thus
+  // before we can detect the client. We must not call RESOLVE_ROOT here because
+  // this might turn out to be a client we want to block.
+  if (!aOptions) {
+    return E_INVALIDARG;
+  }
+  *aOptions = uiaRawElmProvider::kProviderOptions;
+  return S_OK;
+}
+
+STDMETHODIMP
+LazyInstantiator::GetPatternProvider(
+    PATTERNID aPatternId, __RPC__deref_out_opt IUnknown** aPatternProvider) {
+  RESOLVE_ROOT;
+  return mWeakUia->GetPatternProvider(aPatternId, aPatternProvider);
+}
+
+STDMETHODIMP
+LazyInstantiator::GetPropertyValue(PROPERTYID aPropertyId,
+                                   __RPC__out VARIANT* aPropertyValue) {
+  RESOLVE_ROOT;
+  return mWeakUia->GetPropertyValue(aPropertyId, aPropertyValue);
+}
+
+STDMETHODIMP
+LazyInstantiator::get_HostRawElementProvider(
+    __RPC__deref_out_opt IRawElementProviderSimple** aRawElmProvider) {
+  // This method is called before a UIA connection is fully established and thus
+  // before we can detect the client. We must not call RESOLVE_ROOT here because
+  // this might turn out to be a client we want to block.
+  if (!aRawElmProvider) {
+    return E_INVALIDARG;
+  }
+  *aRawElmProvider = nullptr;
+  return UiaHostProviderFromHwnd(mHwnd, aRawElmProvider);
+}
+
 }  // namespace a11y
 }  // namespace mozilla
diff --git a/accessible/windows/msaa/LazyInstantiator.h b/accessible/windows/msaa/LazyInstantiator.h
index 00fa4ba6ed..adbb0f70b5 100644
--- a/accessible/windows/msaa/LazyInstantiator.h
+++ b/accessible/windows/msaa/LazyInstantiator.h
@@ -13,6 +13,7 @@
 #include "nsString.h"
 
 #include <oleacc.h>
+#include <uiautomation.h>
 
 class nsIFile;
 
@@ -29,10 +30,14 @@ class MsaaRootAccessible;
  *     services in order to fulfill; and
  * (2) LazyInstantiator::ShouldInstantiate returns true.
  */
-class LazyInstantiator final : public IAccessible, public IServiceProvider {
+class LazyInstantiator final : public IAccessible,
+                               public IServiceProvider,
+                               public IRawElementProviderSimple {
  public:
   [[nodiscard]] static already_AddRefed<IAccessible> GetRootAccessible(
       HWND aHwnd);
+  [[nodiscard]] static already_AddRefed<IRawElementProviderSimple> GetRootUia(
+      HWND aHwnd);
   static void EnableBlindAggregation(HWND aHwnd);
 
   // IUnknown
@@ -83,6 +88,22 @@ class LazyInstantiator final : public IAccessible, public IServiceProvider {
   STDMETHODIMP QueryService(REFGUID aServiceId, REFIID aServiceIid,
                             void** aOutInterface) override;
 
+  // IRawElementProviderSimple
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_ProviderOptions(
+      /* [retval][out] */ __RPC__out enum ProviderOptions* aProviderOptions);
+
+  virtual HRESULT STDMETHODCALLTYPE GetPatternProvider(
+      /* [in] */ PATTERNID aPatternId,
+      /* [retval][out] */ __RPC__deref_out_opt IUnknown** aPatternProvider);
+
+  virtual HRESULT STDMETHODCALLTYPE GetPropertyValue(
+      /* [in] */ PROPERTYID aPropertyId,
+      /* [retval][out] */ __RPC__out VARIANT* aPropertyValue);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_HostRawElementProvider(
+      /* [retval][out] */ __RPC__deref_out_opt IRawElementProviderSimple**
+          aRawElmProvider);
+
   /**
    * We cache the result of UIA detection because it could be expensive if a
    * client repeatedly queries us. This function is called to reset that cache
@@ -117,6 +138,9 @@ class LazyInstantiator final : public IAccessible, public IServiceProvider {
   void TransplantRefCnt();
   void ClearProp();
 
+  template <class T>
+  static already_AddRefed<T> GetRoot(HWND aHwnd);
+
  private:
   mozilla::a11y::AutoRefCnt mRefCnt;
   HWND mHwnd;
@@ -133,6 +157,7 @@ class LazyInstantiator final : public IAccessible, public IServiceProvider {
   MsaaRootAccessible* mWeakMsaaRoot;
   IAccessible* mWeakAccessible;
   IDispatch* mWeakDispatch;
+  IRawElementProviderSimple* mWeakUia;
   static Maybe<bool> sShouldBlockUia;
 };
 
diff --git a/accessible/windows/msaa/Platform.cpp b/accessible/windows/msaa/Platform.cpp
index f4d1c7b176..eaf9e7c126 100644
--- a/accessible/windows/msaa/Platform.cpp
+++ b/accessible/windows/msaa/Platform.cpp
@@ -129,6 +129,7 @@ void a11y::PlatformShowHideEvent(Accessible* aTarget, Accessible*, bool aInsert,
 void a11y::PlatformSelectionEvent(Accessible* aTarget, Accessible*,
                                   uint32_t aType) {
   MsaaAccessible::FireWinEvent(aTarget, aType);
+  uiaRawElmProvider::RaiseUiaEventForGeckoEvent(aTarget, aType);
 }
 
 static bool GetInstantiatorExecutable(const DWORD aPid,
diff --git a/accessible/windows/uia/UiaGrid.cpp b/accessible/windows/uia/UiaGrid.cpp
new file mode 100644
index 0000000000..2a22a1f4da
--- /dev/null
+++ b/accessible/windows/uia/UiaGrid.cpp
@@ -0,0 +1,151 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* 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 "ia2AccessibleTable.h"
+#include "mozilla/a11y/TableAccessible.h"
+#include "nsIAccessiblePivot.h"
+#include "Pivot.h"
+#include "UiaGrid.h"
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+
+// Helpers
+
+// Used to search for all row and column headers in a table. This could be slow,
+// as it potentially walks all cells in the table. However, it's unclear if,
+// when or how often clients will use this. If this proves to be a performance
+// problem, we will need to add methods to TableAccessible to get all row and
+// column headers in a faster way.
+class HeaderRule : public PivotRule {
+ public:
+  explicit HeaderRule(role aRole) : mRole(aRole) {}
+
+  virtual uint16_t Match(Accessible* aAcc) override {
+    role accRole = aAcc->Role();
+    if (accRole == mRole) {
+      return nsIAccessibleTraversalRule::FILTER_MATCH |
+             nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
+    }
+    if (accRole == roles::CAPTION || aAcc->IsTableCell()) {
+      return nsIAccessibleTraversalRule::FILTER_IGNORE |
+             nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
+    }
+    return nsIAccessibleTraversalRule::FILTER_IGNORE;
+  }
+
+ private:
+  role mRole;
+};
+
+static SAFEARRAY* GetAllHeaders(Accessible* aTable, role aRole) {
+  AutoTArray<Accessible*, 20> headers;
+  Pivot pivot(aTable);
+  HeaderRule rule(aRole);
+  for (Accessible* header = pivot.Next(aTable, rule); header;
+       header = pivot.Next(header, rule)) {
+    headers.AppendElement(header);
+  }
+  return AccessibleArrayToUiaArray(headers);
+}
+
+// UiaGrid
+
+Accessible* UiaGrid::Acc() {
+  auto* ia2t = static_cast<ia2AccessibleTable*>(this);
+  return ia2t->MsaaAccessible::Acc();
+}
+
+TableAccessible* UiaGrid::TableAcc() {
+  Accessible* acc = Acc();
+  return acc ? acc->AsTable() : nullptr;
+}
+
+// IGridProvider methods
+
+STDMETHODIMP
+UiaGrid::GetItem(int aRow, int aColumn,
+                 __RPC__deref_out_opt IRawElementProviderSimple** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  *aRetVal = nullptr;
+  TableAccessible* table = TableAcc();
+  if (!table) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  Accessible* cell = table->CellAt(aRow, aColumn);
+  if (!cell) {
+    return E_INVALIDARG;
+  }
+  RefPtr<IRawElementProviderSimple> uia = MsaaAccessible::GetFrom(cell);
+  uia.forget(aRetVal);
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGrid::get_RowCount(__RPC__out int* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  TableAccessible* table = TableAcc();
+  if (!table) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = table->RowCount();
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGrid::get_ColumnCount(__RPC__out int* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  TableAccessible* table = TableAcc();
+  if (!table) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = table->ColCount();
+  return S_OK;
+}
+
+// ITableProvider methods
+
+STDMETHODIMP
+UiaGrid::GetRowHeaders(__RPC__deref_out_opt SAFEARRAY** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = GetAllHeaders(acc, roles::ROWHEADER);
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGrid::GetColumnHeaders(__RPC__deref_out_opt SAFEARRAY** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = GetAllHeaders(acc, roles::COLUMNHEADER);
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGrid::get_RowOrColumnMajor(__RPC__out enum RowOrColumnMajor* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  // HTML and ARIA tables are always in row major order.
+  *aRetVal = RowOrColumnMajor_RowMajor;
+  return S_OK;
+}
diff --git a/accessible/windows/uia/UiaGrid.h b/accessible/windows/uia/UiaGrid.h
new file mode 100644
index 0000000000..c38442246c
--- /dev/null
+++ b/accessible/windows/uia/UiaGrid.h
@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* 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_a11y_UiaGrid_h__
+#define mozilla_a11y_UiaGrid_h__
+
+#include "objbase.h"
+#include "uiautomation.h"
+
+namespace mozilla::a11y {
+class Accessible;
+class TableAccessible;
+
+/**
+ * IGridProvider and ITableProvider implementations.
+ */
+class UiaGrid : public IGridProvider, public ITableProvider {
+ public:
+  // IGridProvider
+  virtual HRESULT STDMETHODCALLTYPE GetItem(
+      /* [in] */ int aRow,
+      /* [in] */ int aColumn,
+      /* [retval][out] */
+      __RPC__deref_out_opt IRawElementProviderSimple** aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_RowCount(
+      /* [retval][out] */ __RPC__out int* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_ColumnCount(
+      /* [retval][out] */ __RPC__out int* aRetVal);
+
+  // ITableProvider
+  virtual HRESULT STDMETHODCALLTYPE GetRowHeaders(
+      /* [retval][out] */ __RPC__deref_out_opt SAFEARRAY** aRetVal);
+
+  virtual HRESULT STDMETHODCALLTYPE GetColumnHeaders(
+      /* [retval][out] */ __RPC__deref_out_opt SAFEARRAY** aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_RowOrColumnMajor(
+      /* [retval][out] */ __RPC__out enum RowOrColumnMajor* aRetVal);
+
+ private:
+  Accessible* Acc();
+  TableAccessible* TableAcc();
+};
+
+}  // namespace mozilla::a11y
+
+#endif
diff --git a/accessible/windows/uia/UiaGridItem.cpp b/accessible/windows/uia/UiaGridItem.cpp
new file mode 100644
index 0000000000..89c56b8d45
--- /dev/null
+++ b/accessible/windows/uia/UiaGridItem.cpp
@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* 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 "ia2AccessibleTableCell.h"
+#include "mozilla/a11y/TableAccessible.h"
+#include "mozilla/a11y/TableCellAccessible.h"
+#include "UiaGridItem.h"
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+
+// UiaGridItem
+
+TableCellAccessible* UiaGridItem::CellAcc() {
+  auto* derived = static_cast<ia2AccessibleTableCell*>(this);
+  Accessible* acc = derived->Acc();
+  return acc ? acc->AsTableCell() : nullptr;
+}
+
+// IGridItemProvider methods
+
+STDMETHODIMP
+UiaGridItem::get_Row(__RPC__out int* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  TableCellAccessible* cell = CellAcc();
+  if (!cell) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = cell->RowIdx();
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGridItem::get_Column(__RPC__out int* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  TableCellAccessible* cell = CellAcc();
+  if (!cell) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = cell->ColIdx();
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGridItem::get_RowSpan(__RPC__out int* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  TableCellAccessible* cell = CellAcc();
+  if (!cell) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = cell->RowExtent();
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGridItem::get_ColumnSpan(__RPC__out int* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  TableCellAccessible* cell = CellAcc();
+  if (!cell) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = cell->ColExtent();
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGridItem::get_ContainingGrid(
+    __RPC__deref_out_opt IRawElementProviderSimple** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  *aRetVal = nullptr;
+  TableCellAccessible* cell = CellAcc();
+  if (!cell) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  TableAccessible* table = cell->Table();
+  if (!table) {
+    return E_FAIL;
+  }
+  Accessible* tableAcc = table->AsAccessible();
+  RefPtr<IRawElementProviderSimple> uia = MsaaAccessible::GetFrom(tableAcc);
+  uia.forget(aRetVal);
+  return S_OK;
+}
+
+// ITableItemProvider methods
+
+STDMETHODIMP
+UiaGridItem::GetRowHeaderItems(__RPC__deref_out_opt SAFEARRAY** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  *aRetVal = nullptr;
+  TableCellAccessible* cell = CellAcc();
+  if (!cell) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  AutoTArray<Accessible*, 10> cells;
+  cell->RowHeaderCells(&cells);
+  *aRetVal = AccessibleArrayToUiaArray(cells);
+  return S_OK;
+}
+
+STDMETHODIMP
+UiaGridItem::GetColumnHeaderItems(__RPC__deref_out_opt SAFEARRAY** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  *aRetVal = nullptr;
+  TableCellAccessible* cell = CellAcc();
+  if (!cell) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  AutoTArray<Accessible*, 10> cells;
+  cell->ColHeaderCells(&cells);
+  *aRetVal = AccessibleArrayToUiaArray(cells);
+  return S_OK;
+}
diff --git a/accessible/windows/uia/UiaGridItem.h b/accessible/windows/uia/UiaGridItem.h
new file mode 100644
index 0000000000..6c59630b0f
--- /dev/null
+++ b/accessible/windows/uia/UiaGridItem.h
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* 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_a11y_UiaGridItem_h__
+#define mozilla_a11y_UiaGridItem_h__
+
+#include "objbase.h"
+#include "uiautomation.h"
+
+namespace mozilla::a11y {
+class TableCellAccessible;
+
+/**
+ * IGridItemProvider and ITableItemProvider implementations.
+ */
+class UiaGridItem : public IGridItemProvider, public ITableItemProvider {
+ public:
+  // IGridItemProvider
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_Row(
+      /* [retval][out] */ __RPC__out int* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_Column(
+      /* [retval][out] */ __RPC__out int* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_RowSpan(
+      /* [retval][out] */ __RPC__out int* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_ColumnSpan(
+      /* [retval][out] */ __RPC__out int* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_ContainingGrid(
+      /* [retval][out] */ __RPC__deref_out_opt IRawElementProviderSimple**
+          aRetVal);
+
+  // ITableItemProvider
+  virtual HRESULT STDMETHODCALLTYPE GetRowHeaderItems(
+      /* [retval][out] */ __RPC__deref_out_opt SAFEARRAY** aRetVal);
+
+  virtual HRESULT STDMETHODCALLTYPE GetColumnHeaderItems(
+      /* [retval][out] */ __RPC__deref_out_opt SAFEARRAY** aRetVal);
+
+ private:
+  TableCellAccessible* CellAcc();
+};
+
+}  // namespace mozilla::a11y
+
+#endif
diff --git a/accessible/windows/uia/moz.build b/accessible/windows/uia/moz.build
index c52a24d612..2061261494 100644
--- a/accessible/windows/uia/moz.build
+++ b/accessible/windows/uia/moz.build
@@ -5,6 +5,8 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 SOURCES += [
+    "UiaGrid.cpp",
+    "UiaGridItem.cpp",
     "uiaRawElmProvider.cpp",
     "UiaRoot.cpp",
 ]
@@ -13,6 +15,7 @@ LOCAL_INCLUDES += [
     "/accessible/base",
     "/accessible/generic",
     "/accessible/html",
+    "/accessible/windows/ia2",
     "/accessible/windows/msaa",
     "/accessible/xpcom",
     "/accessible/xul",
diff --git a/accessible/windows/uia/uiaRawElmProvider.cpp b/accessible/windows/uia/uiaRawElmProvider.cpp
index c022e40cef..82726bb9aa 100644
--- a/accessible/windows/uia/uiaRawElmProvider.cpp
+++ b/accessible/windows/uia/uiaRawElmProvider.cpp
@@ -11,7 +11,10 @@
 
 #include "AccAttributes.h"
 #include "AccessibleWrap.h"
+#include "ApplicationAccessible.h"
 #include "ARIAMap.h"
+#include "ia2AccessibleTable.h"
+#include "ia2AccessibleTableCell.h"
 #include "LocalAccessible-inl.h"
 #include "mozilla/a11y/RemoteAccessible.h"
 #include "mozilla/StaticPrefs_accessibility.h"
@@ -19,12 +22,25 @@
 #include "MsaaRootAccessible.h"
 #include "nsAccessibilityService.h"
 #include "nsAccUtils.h"
+#include "nsIAccessiblePivot.h"
 #include "nsTextEquivUtils.h"
+#include "Pivot.h"
+#include "Relation.h"
 #include "RootAccessible.h"
 
 using namespace mozilla;
 using namespace mozilla::a11y;
 
+#ifdef __MINGW32__
+// These constants are missing in mingw-w64. This code should be removed once
+// we update to a version which includes them.
+const long UIA_CustomLandmarkTypeId = 80000;
+const long UIA_FormLandmarkTypeId = 80001;
+const long UIA_MainLandmarkTypeId = 80002;
+const long UIA_NavigationLandmarkTypeId = 80003;
+const long UIA_SearchLandmarkTypeId = 80004;
+#endif  // __MINGW32__
+
 // Helper functions
 
 static ToggleState ToToggleState(uint64_t aState) {
@@ -51,6 +67,34 @@ static ExpandCollapseState ToExpandCollapseState(uint64_t aState) {
   return ExpandCollapseState_LeafNode;
 }
 
+static bool IsRadio(Accessible* aAcc) {
+  role r = aAcc->Role();
+  return r == roles::RADIOBUTTON || r == roles::RADIO_MENU_ITEM;
+}
+
+// Used to search for a text leaf descendant for the LabeledBy property.
+class LabelTextLeafRule : public PivotRule {
+ public:
+  virtual uint16_t Match(Accessible* aAcc) override {
+    if (aAcc->IsTextLeaf()) {
+      nsAutoString name;
+      aAcc->Name(name);
+      if (name.IsEmpty() || name.EqualsLiteral(" ")) {
+        // An empty or white space text leaf isn't useful as a label.
+        return nsIAccessibleTraversalRule::FILTER_IGNORE;
+      }
+      return nsIAccessibleTraversalRule::FILTER_MATCH;
+    }
+    if (!nsTextEquivUtils::HasNameRule(aAcc, eNameFromSubtreeIfReqRule)) {
+      // Don't descend into things that can't be used as label content; e.g.
+      // text boxes.
+      return nsIAccessibleTraversalRule::FILTER_IGNORE |
+             nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
+    }
+    return nsIAccessibleTraversalRule::FILTER_IGNORE;
+  }
+};
+
 ////////////////////////////////////////////////////////////////////////////////
 // uiaRawElmProvider
 ////////////////////////////////////////////////////////////////////////////////
@@ -84,12 +128,32 @@ void uiaRawElmProvider::RaiseUiaEventForGeckoEvent(Accessible* aAcc,
     case nsIAccessibleEvent::EVENT_NAME_CHANGE:
       property = UIA_NamePropertyId;
       break;
+    case nsIAccessibleEvent::EVENT_SELECTION:
+      ::UiaRaiseAutomationEvent(uia, UIA_SelectionItem_ElementSelectedEventId);
+      return;
+    case nsIAccessibleEvent::EVENT_SELECTION_ADD:
+      ::UiaRaiseAutomationEvent(
+          uia, UIA_SelectionItem_ElementAddedToSelectionEventId);
+      return;
+    case nsIAccessibleEvent::EVENT_SELECTION_REMOVE:
+      ::UiaRaiseAutomationEvent(
+          uia, UIA_SelectionItem_ElementRemovedFromSelectionEventId);
+      return;
+    case nsIAccessibleEvent::EVENT_SELECTION_WITHIN:
+      ::UiaRaiseAutomationEvent(uia, UIA_Selection_InvalidatedEventId);
+      return;
     case nsIAccessibleEvent::EVENT_TEXT_VALUE_CHANGE:
       property = UIA_ValueValuePropertyId;
       newVal.vt = VT_BSTR;
       uia->get_Value(&newVal.bstrVal);
       gotNewVal = true;
       break;
+    case nsIAccessibleEvent::EVENT_VALUE_CHANGE:
+      property = UIA_RangeValueValuePropertyId;
+      newVal.vt = VT_R8;
+      uia->get_Value(&newVal.dblVal);
+      gotNewVal = true;
+      break;
   }
   if (property && ::UiaClientsAreListening()) {
     // We can't get the old value. Thankfully, clients don't seem to need it.
@@ -117,6 +181,13 @@ void uiaRawElmProvider::RaiseUiaEventForStateChange(Accessible* aAcc,
   _variant_t newVal;
   switch (aState) {
     case states::CHECKED:
+      if (aEnabled && IsRadio(aAcc)) {
+        ::UiaRaiseAutomationEvent(uia,
+                                  UIA_SelectionItem_ElementSelectedEventId);
+        return;
+      }
+      // For other checkable things, the Toggle pattern is used.
+      [[fallthrough]];
     case states::MIXED:
     case states::PRESSED:
       property = UIA_ToggleToggleStatePropertyId;
@@ -161,8 +232,14 @@ uiaRawElmProvider::QueryInterface(REFIID aIid, void** aInterface) {
     *aInterface = static_cast<IExpandCollapseProvider*>(this);
   } else if (aIid == IID_IInvokeProvider) {
     *aInterface = static_cast<IInvokeProvider*>(this);
+  } else if (aIid == IID_IRangeValueProvider) {
+    *aInterface = static_cast<IRangeValueProvider*>(this);
   } else if (aIid == IID_IScrollItemProvider) {
     *aInterface = static_cast<IScrollItemProvider*>(this);
+  } else if (aIid == IID_ISelectionItemProvider) {
+    *aInterface = static_cast<ISelectionItemProvider*>(this);
+  } else if (aIid == IID_ISelectionProvider) {
+    *aInterface = static_cast<ISelectionProvider*>(this);
   } else if (aIid == IID_IToggleProvider) {
     *aInterface = static_cast<IToggleProvider*>(this);
   } else if (aIid == IID_IValueProvider) {
@@ -248,9 +325,7 @@ uiaRawElmProvider::get_ProviderOptions(
     __RPC__out enum ProviderOptions* aOptions) {
   if (!aOptions) return E_INVALIDARG;
 
-  *aOptions = static_cast<enum ProviderOptions>(
-      ProviderOptions_ServerSideProvider | ProviderOptions_UseComThreading |
-      ProviderOptions_HasNativeIAccessible);
+  *aOptions = kProviderOptions;
   return S_OK;
 }
 
@@ -270,21 +345,78 @@ uiaRawElmProvider::GetPatternProvider(
         expand.forget(aPatternProvider);
       }
       return S_OK;
+    case UIA_GridPatternId:
+      if (acc->IsTable()) {
+        auto grid = GetPatternFromDerived<ia2AccessibleTable, IGridProvider>();
+        grid.forget(aPatternProvider);
+      }
+      return S_OK;
+    case UIA_GridItemPatternId:
+      if (acc->IsTableCell()) {
+        auto item =
+            GetPatternFromDerived<ia2AccessibleTableCell, IGridItemProvider>();
+        item.forget(aPatternProvider);
+      }
+      return S_OK;
     case UIA_InvokePatternId:
       // Per the UIA documentation, we should only expose the Invoke pattern "if
       // the same behavior is not exposed through another control pattern
       // provider".
       if (acc->ActionCount() > 0 && !HasTogglePattern() &&
-          !HasExpandCollapsePattern()) {
+          !HasExpandCollapsePattern() && !HasSelectionItemPattern()) {
         RefPtr<IInvokeProvider> invoke = this;
         invoke.forget(aPatternProvider);
       }
       return S_OK;
+    case UIA_RangeValuePatternId:
+      if (acc->HasNumericValue()) {
+        RefPtr<IValueProvider> value = this;
+        value.forget(aPatternProvider);
+      }
+      return S_OK;
     case UIA_ScrollItemPatternId: {
       RefPtr<IScrollItemProvider> scroll = this;
       scroll.forget(aPatternProvider);
       return S_OK;
     }
+    case UIA_SelectionItemPatternId:
+      if (HasSelectionItemPattern()) {
+        RefPtr<ISelectionItemProvider> item = this;
+        item.forget(aPatternProvider);
+      }
+      return S_OK;
+    case UIA_SelectionPatternId:
+      // According to the UIA documentation, radio button groups should support
+      // the Selection pattern. However:
+      // 1. The Core AAM spec doesn't specify the Selection pattern for
+      // the radiogroup role.
+      // 2. HTML radio buttons might not be contained by a dedicated group.
+      // 3. Chromium exposes the Selection pattern on radio groups, but it
+      // doesn't expose any selected items, even when there is a checked radio
+      // child.
+      // 4. Radio menu items are similar to radio buttons and all the above
+      // also applies to menus.
+      // For now, we don't support the Selection pattern for radio groups or
+      // menus, only for list boxes, tab lists, etc.
+      if (acc->IsSelect()) {
+        RefPtr<ISelectionProvider> selection = this;
+        selection.forget(aPatternProvider);
+      }
+      return S_OK;
+    case UIA_TablePatternId:
+      if (acc->IsTable()) {
+        auto table =
+            GetPatternFromDerived<ia2AccessibleTable, ITableProvider>();
+        table.forget(aPatternProvider);
+      }
+      return S_OK;
+    case UIA_TableItemPatternId:
+      if (acc->IsTableCell()) {
+        auto item =
+            GetPatternFromDerived<ia2AccessibleTableCell, ITableItemProvider>();
+        item.forget(aPatternProvider);
+      }
+      return S_OK;
     case UIA_TogglePatternId:
       if (HasTogglePattern()) {
         RefPtr<IToggleProvider> toggle = this;
@@ -349,19 +481,19 @@ uiaRawElmProvider::GetPropertyValue(PROPERTYID aPropertyId,
       break;
     }
 
-    // ARIA Role / shortcut
     case UIA_AriaRolePropertyId: {
-      nsAutoString xmlRoles;
-
-      RefPtr<AccAttributes> attributes = acc->Attributes();
-      attributes->GetAttribute(nsGkAtoms::xmlroles, xmlRoles);
-
-      if (!xmlRoles.IsEmpty()) {
+      nsAutoString role;
+      if (acc->HasARIARole()) {
+        RefPtr<AccAttributes> attributes = acc->Attributes();
+        attributes->GetAttribute(nsGkAtoms::xmlroles, role);
+      } else if (nsStaticAtom* computed = acc->ComputedARIARole()) {
+        computed->ToString(role);
+      }
+      if (!role.IsEmpty()) {
         aPropertyValue->vt = VT_BSTR;
-        aPropertyValue->bstrVal = ::SysAllocString(xmlRoles.get());
+        aPropertyValue->bstrVal = ::SysAllocString(role.get());
         return S_OK;
       }
-
       break;
     }
 
@@ -415,11 +547,57 @@ uiaRawElmProvider::GetPropertyValue(PROPERTYID aPropertyId,
       break;
     }
 
+    case UIA_ClassNamePropertyId: {
+      nsAutoString className;
+      acc->DOMNodeClass(className);
+      if (!className.IsEmpty()) {
+        aPropertyValue->vt = VT_BSTR;
+        aPropertyValue->bstrVal = ::SysAllocString(className.get());
+        return S_OK;
+      }
+      break;
+    }
+
+    case UIA_ControllerForPropertyId:
+      aPropertyValue->vt = VT_UNKNOWN | VT_ARRAY;
+      aPropertyValue->parray = AccRelationsToUiaArray(
+          {RelationType::CONTROLLER_FOR, RelationType::ERRORMSG});
+      return S_OK;
+
     case UIA_ControlTypePropertyId:
       aPropertyValue->vt = VT_I4;
       aPropertyValue->lVal = GetControlType();
       break;
 
+    case UIA_DescribedByPropertyId:
+      aPropertyValue->vt = VT_UNKNOWN | VT_ARRAY;
+      aPropertyValue->parray = AccRelationsToUiaArray(
+          {RelationType::DESCRIBED_BY, RelationType::DETAILS});
+      return S_OK;
+
+    case UIA_FlowsFromPropertyId:
+      aPropertyValue->vt = VT_UNKNOWN | VT_ARRAY;
+      aPropertyValue->parray =
+          AccRelationsToUiaArray({RelationType::FLOWS_FROM});
+      return S_OK;
+
+    case UIA_FlowsToPropertyId:
+      aPropertyValue->vt = VT_UNKNOWN | VT_ARRAY;
+      aPropertyValue->parray = AccRelationsToUiaArray({RelationType::FLOWS_TO});
+      return S_OK;
+
+    case UIA_FrameworkIdPropertyId:
+      if (ApplicationAccessible* app = ApplicationAcc()) {
+        nsAutoString name;
+        app->PlatformName(name);
+        if (!name.IsEmpty()) {
+          aPropertyValue->vt = VT_BSTR;
+          aPropertyValue->bstrVal = ::SysAllocString(name.get());
+          return S_OK;
+        }
+      }
+      break;
+
     case UIA_FullDescriptionPropertyId: {
       nsAutoString desc;
       acc->Description(desc);
@@ -459,6 +637,39 @@ uiaRawElmProvider::GetPropertyValue(PROPERTYID aPropertyId,
           (acc->State() & states::FOCUSABLE) ? VARIANT_TRUE : VARIANT_FALSE;
       return S_OK;
 
+    case UIA_LabeledByPropertyId:
+      if (Accessible* target = GetLabeledBy()) {
+        aPropertyValue->vt = VT_UNKNOWN;
+        RefPtr<IRawElementProviderSimple> uia = MsaaAccessible::GetFrom(target);
+        uia.forget(&aPropertyValue->punkVal);
+        return S_OK;
+      }
+      break;
+
+    case UIA_LandmarkTypePropertyId:
+      if (long type = GetLandmarkType()) {
+        aPropertyValue->vt = VT_I4;
+        aPropertyValue->lVal = type;
+        return S_OK;
+      }
+      break;
+
+    case UIA_LevelPropertyId:
+      aPropertyValue->vt = VT_I4;
+      aPropertyValue->lVal = acc->GroupPosition().level;
+      return S_OK;
+
+    case UIA_LocalizedLandmarkTypePropertyId: {
+      nsAutoString landmark;
+      GetLocalizedLandmarkType(landmark);
+      if (!landmark.IsEmpty()) {
+        aPropertyValue->vt = VT_BSTR;
+        aPropertyValue->bstrVal = ::SysAllocString(landmark.get());
+        return S_OK;
+      }
+      break;
+    }
+
     case UIA_NamePropertyId: {
       nsAutoString name;
       acc->Name(name);
@@ -469,6 +680,16 @@ uiaRawElmProvider::GetPropertyValue(PROPERTYID aPropertyId,
       }
       break;
     }
+
+    case UIA_PositionInSetPropertyId:
+      aPropertyValue->vt = VT_I4;
+      aPropertyValue->lVal = acc->GroupPosition().posInSet;
+      return S_OK;
+
+    case UIA_SizeOfSetPropertyId:
+      aPropertyValue->vt = VT_I4;
+      aPropertyValue->lVal = acc->GroupPosition().setSize;
+      return S_OK;
   }
 
   return S_OK;
@@ -749,6 +970,223 @@ uiaRawElmProvider::get_IsReadOnly(__RPC__out BOOL* aRetVal) {
   return S_OK;
 }
 
+// IRangeValueProvider methods
+
+STDMETHODIMP
+uiaRawElmProvider::SetValue(double aVal) {
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  if (!acc->SetCurValue(aVal)) {
+    return UIA_E_INVALIDOPERATION;
+  }
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_Value(__RPC__out double* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = acc->CurValue();
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_Maximum(__RPC__out double* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = acc->MaxValue();
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_Minimum(
+    /* [retval][out] */ __RPC__out double* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = acc->MinValue();
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_LargeChange(
+    /* [retval][out] */ __RPC__out double* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  // We want the change that would occur if the user pressed page up or page
+  // down. For HTML input elements, this is 10% of the total range unless step
+  // is larger. See:
+  // https://searchfox.org/mozilla-central/rev/c7df16ffad1f12a19c81c16bce0b65e4a15304d0/dom/html/HTMLInputElement.cpp#3878
+  double step = acc->Step();
+  double min = acc->MinValue();
+  double max = acc->MaxValue();
+  if (std::isnan(step) || std::isnan(min) || std::isnan(max)) {
+    *aRetVal = UnspecifiedNaN<double>();
+  } else {
+    *aRetVal = std::max(step, (max - min) / 10);
+  }
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_SmallChange(
+    /* [retval][out] */ __RPC__out double* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = acc->Step();
+  return S_OK;
+}
+
+// ISelectionProvider methods
+
+STDMETHODIMP
+uiaRawElmProvider::GetSelection(__RPC__deref_out_opt SAFEARRAY** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  *aRetVal = nullptr;
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  AutoTArray<Accessible*, 10> items;
+  acc->SelectedItems(&items);
+  *aRetVal = AccessibleArrayToUiaArray(items);
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_CanSelectMultiple(__RPC__out BOOL* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = acc->State() & states::MULTISELECTABLE;
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_IsSelectionRequired(__RPC__out BOOL* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  *aRetVal = acc->State() & states::REQUIRED;
+  return S_OK;
+}
+
+// ISelectionItemProvider methods
+
+STDMETHODIMP
+uiaRawElmProvider::Select() {
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  if (IsRadio(acc)) {
+    acc->DoAction(0);
+  } else {
+    acc->TakeSelection();
+  }
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::AddToSelection() {
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  if (IsRadio(acc)) {
+    acc->DoAction(0);
+  } else {
+    acc->SetSelected(true);
+  }
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::RemoveFromSelection() {
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  if (IsRadio(acc)) {
+    return UIA_E_INVALIDOPERATION;
+  }
+  acc->SetSelected(false);
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_IsSelected(__RPC__out BOOL* aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  if (IsRadio(acc)) {
+    *aRetVal = acc->State() & states::CHECKED;
+  } else {
+    *aRetVal = acc->State() & states::SELECTED;
+  }
+  return S_OK;
+}
+
+STDMETHODIMP
+uiaRawElmProvider::get_SelectionContainer(
+    __RPC__deref_out_opt IRawElementProviderSimple** aRetVal) {
+  if (!aRetVal) {
+    return E_INVALIDARG;
+  }
+  *aRetVal = nullptr;
+  Accessible* acc = Acc();
+  if (!acc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+  Accessible* container = nsAccUtils::GetSelectableContainer(acc, acc->State());
+  if (!container) {
+    return E_FAIL;
+  }
+  RefPtr<IRawElementProviderSimple> uia = MsaaAccessible::GetFrom(container);
+  uia.forget(aRetVal);
+  return S_OK;
+}
+
 // Private methods
 
 bool uiaRawElmProvider::IsControl() {
@@ -854,3 +1292,133 @@ bool uiaRawElmProvider::HasValuePattern() const {
   const nsRoleMapEntry* roleMapEntry = acc->ARIARoleMap();
   return roleMapEntry && roleMapEntry->Is(nsGkAtoms::textbox);
 }
+
+template <class Derived, class Interface>
+RefPtr<Interface> uiaRawElmProvider::GetPatternFromDerived() {
+  // MsaaAccessible inherits from uiaRawElmProvider. Derived
+  // inherits from MsaaAccessible and Interface. The compiler won't let us
+  // directly static_cast to Interface, hence the intermediate casts.
+  auto* msaa = static_cast<MsaaAccessible*>(this);
+  auto* derived = static_cast<Derived*>(msaa);
+  return derived;
+}
+
+bool uiaRawElmProvider::HasSelectionItemPattern() {
+  Accessible* acc = Acc();
+  MOZ_ASSERT(acc);
+  // In UIA, radio buttons and radio menu items are exposed as selected or
+  // unselected.
+  return acc->State() & states::SELECTABLE || IsRadio(acc);
+}
+
+SAFEARRAY* uiaRawElmProvider::AccRelationsToUiaArray(
+    std::initializer_list<RelationType> aTypes) const {
+  Accessible* acc = Acc();
+  MOZ_ASSERT(acc);
+  AutoTArray<Accessible*, 10> targets;
+  for (RelationType type : aTypes) {
+    Relation rel = acc->RelationByType(type);
+    while (Accessible* target = rel.Next()) {
+      targets.AppendElement(target);
+    }
+  }
+  return AccessibleArrayToUiaArray(targets);
+}
+
+Accessible* uiaRawElmProvider::GetLabeledBy() const {
+  // Per the UIA documentation, some control types should never get a value for
+  // the LabeledBy property.
+  switch (GetControlType()) {
+    case UIA_ButtonControlTypeId:
+    case UIA_CheckBoxControlTypeId:
+    case UIA_DataItemControlTypeId:
+    case UIA_MenuControlTypeId:
+    case UIA_MenuBarControlTypeId:
+    case UIA_RadioButtonControlTypeId:
+    case UIA_ScrollBarControlTypeId:
+    case UIA_SeparatorControlTypeId:
+    case UIA_StatusBarControlTypeId:
+    case UIA_TabItemControlTypeId:
+    case UIA_TextControlTypeId:
+    case UIA_ToolBarControlTypeId:
+    case UIA_ToolTipControlTypeId:
+    case UIA_TreeItemControlTypeId:
+      return nullptr;
+  }
+
+  Accessible* acc = Acc();
+  MOZ_ASSERT(acc);
+  // Even when LabeledBy is supported, it can only return a single "static text"
+  // element.
+  Relation rel = acc->RelationByType(RelationType::LABELLED_BY);
+  LabelTextLeafRule rule;
+  while (Accessible* target = rel.Next()) {
+    // If target were a text leaf, we should return that, but that shouldn't be
+    // possible because only an element (not a text node) can be the target of a
+    // relation.
+    MOZ_ASSERT(!target->IsTextLeaf());
+    Pivot pivot(target);
+    if (Accessible* leaf = pivot.Next(target, rule)) {
+      return leaf;
+    }
+  }
+  return nullptr;
+}
+
+long uiaRawElmProvider::GetLandmarkType() const {
+  Accessible* acc = Acc();
+  MOZ_ASSERT(acc);
+  nsStaticAtom* landmark = acc->LandmarkRole();
+  if (!landmark) {
+    return 0;
+  }
+  if (landmark == nsGkAtoms::form) {
+    return UIA_FormLandmarkTypeId;
+  }
+  if (landmark == nsGkAtoms::main) {
+    return UIA_MainLandmarkTypeId;
+  }
+  if (landmark == nsGkAtoms::navigation) {
+    return UIA_NavigationLandmarkTypeId;
+  }
+  if (landmark == nsGkAtoms::search) {
+    return UIA_SearchLandmarkTypeId;
+  }
+  return UIA_CustomLandmarkTypeId;
+}
+
+void uiaRawElmProvider::GetLocalizedLandmarkType(nsAString& aLocalized) const {
+  Accessible* acc = Acc();
+  MOZ_ASSERT(acc);
+  nsStaticAtom* landmark = acc->LandmarkRole();
+  // The system provides strings for landmarks explicitly supported by the UIA
+  // LandmarkType property; i.e. form, main, navigation and search. We must
+  // provide strings for landmarks considered custom by UIA. For now, we only
+  // support landmarks in the core ARIA specification, not other ARIA modules
+  // such as DPub.
+  if (landmark == nsGkAtoms::banner || landmark == nsGkAtoms::complementary ||
+      landmark == nsGkAtoms::contentinfo || landmark == nsGkAtoms::region) {
+    nsAutoString unlocalized;
+    landmark->ToString(unlocalized);
+    Accessible::TranslateString(unlocalized, aLocalized);
+  }
+}
+
+SAFEARRAY* a11y::AccessibleArrayToUiaArray(const nsTArray<Accessible*>& aAccs) {
+  if (aAccs.IsEmpty()) {
+    // The UIA documentation is unclear about this, but the UIA client
+    // framework seems to treat a null value the same as an empty array. This
+    // is also what Chromium does.
+    return nullptr;
+  }
+  SAFEARRAY* uias = SafeArrayCreateVector(VT_UNKNOWN, 0, aAccs.Length());
+  LONG indices[1] = {0};
+  for (Accessible* acc : aAccs) {
+    // SafeArrayPutElement calls AddRef on the element, so we use a raw pointer
+    // here.
+    IRawElementProviderSimple* uia = MsaaAccessible::GetFrom(acc);
+    SafeArrayPutElement(uias, indices, uia);
+    ++indices[0];
+  }
+  return uias;
+}
diff --git a/accessible/windows/uia/uiaRawElmProvider.h b/accessible/windows/uia/uiaRawElmProvider.h
index 0e05d1a030..ea713d8bc1 100644
--- a/accessible/windows/uia/uiaRawElmProvider.h
+++ b/accessible/windows/uia/uiaRawElmProvider.h
@@ -11,10 +11,20 @@
 #include <stdint.h>
 #include <uiautomation.h>
 
+#include <initializer_list>
+
+#include "nsString.h"
+
+template <class T>
+class nsTArray;
+template <class T>
+class RefPtr;
+
 namespace mozilla {
 namespace a11y {
 
 class Accessible;
+enum class RelationType;
 
 /**
  * IRawElementProviderSimple implementation (maintains IAccessibleEx approach).
@@ -26,8 +36,16 @@ class uiaRawElmProvider : public IAccessibleEx,
                           public IToggleProvider,
                           public IExpandCollapseProvider,
                           public IScrollItemProvider,
-                          public IValueProvider {
+                          public IValueProvider,
+                          public IRangeValueProvider,
+                          public ISelectionProvider,
+                          public ISelectionItemProvider {
  public:
+  static constexpr enum ProviderOptions kProviderOptions =
+      static_cast<enum ProviderOptions>(ProviderOptions_ServerSideProvider |
+                                        ProviderOptions_UseComThreading |
+                                        ProviderOptions_HasNativeIAccessible);
+
   static void RaiseUiaEventForGeckoEvent(Accessible* aAcc,
                                          uint32_t aGeckoEvent);
   static void RaiseUiaEventForStateChange(Accessible* aAcc, uint64_t aState,
@@ -118,6 +136,51 @@ class uiaRawElmProvider : public IAccessibleEx,
   virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_IsReadOnly(
       /* [retval][out] */ __RPC__out BOOL* pRetVal);
 
+  // IRangeValueProvider
+  virtual HRESULT STDMETHODCALLTYPE SetValue(
+      /* [in] */ double aVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_Value(
+      /* [retval][out] */ __RPC__out double* aRetVal);
+
+  // get_IsReadOnly is shared with IValueProvider.
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_Maximum(
+      /* [retval][out] */ __RPC__out double* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_Minimum(
+      /* [retval][out] */ __RPC__out double* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_LargeChange(
+      /* [retval][out] */ __RPC__out double* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_SmallChange(
+      /* [retval][out] */ __RPC__out double* aRetVal);
+
+  // ISelectionProvider
+  virtual HRESULT STDMETHODCALLTYPE GetSelection(
+      /* [retval][out] */ __RPC__deref_out_opt SAFEARRAY** aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_CanSelectMultiple(
+      /* [retval][out] */ __RPC__out BOOL* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_IsSelectionRequired(
+      /* [retval][out] */ __RPC__out BOOL* aRetVal);
+
+  // ISelectionItemProvider methods
+  virtual HRESULT STDMETHODCALLTYPE Select(void);
+
+  virtual HRESULT STDMETHODCALLTYPE AddToSelection(void);
+
+  virtual HRESULT STDMETHODCALLTYPE RemoveFromSelection(void);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_IsSelected(
+      /* [retval][out] */ __RPC__out BOOL* aRetVal);
+
+  virtual /* [propget] */ HRESULT STDMETHODCALLTYPE get_SelectionContainer(
+      /* [retval][out] */ __RPC__deref_out_opt IRawElementProviderSimple**
+          aRetVal);
+
  private:
   Accessible* Acc() const;
   bool IsControl();
@@ -125,8 +188,18 @@ class uiaRawElmProvider : public IAccessibleEx,
   bool HasTogglePattern();
   bool HasExpandCollapsePattern();
   bool HasValuePattern() const;
+  template <class Derived, class Interface>
+  RefPtr<Interface> GetPatternFromDerived();
+  bool HasSelectionItemPattern();
+  SAFEARRAY* AccRelationsToUiaArray(
+      std::initializer_list<RelationType> aTypes) const;
+  Accessible* GetLabeledBy() const;
+  long GetLandmarkType() const;
+  void GetLocalizedLandmarkType(nsAString& aLocalized) const;
 };
 
+SAFEARRAY* AccessibleArrayToUiaArray(const nsTArray<Accessible*>& aAccs);
+
 }  // namespace a11y
 }  // namespace mozilla
 
diff --git a/accessible/xpcom/xpcAccessibilityService.cpp b/accessible/xpcom/xpcAccessibilityService.cpp
index a7b70b6f33..f6692bffbb 100644
--- a/accessible/xpcom/xpcAccessibilityService.cpp
+++ b/accessible/xpcom/xpcAccessibilityService.cpp
@@ -123,7 +123,8 @@ xpcAccessibilityService::GetAccessibleFor(nsINode* aNode,
 
   DocAccessible* document = accService->GetDocAccessible(aNode->OwnerDoc());
   if (document) {
-    NS_IF_ADDREF(*aAccessible = ToXPC(document->GetAccessible(aNode)));
+    NS_IF_ADDREF(*aAccessible =
+                     ToXPC(document->GetAccessibleEvenIfNotInMap(aNode)));
   }
 
   return NS_OK;