--- a/accessible/generic/Accessible.cpp
+++ b/accessible/generic/Accessible.cpp
@@ -2569,17 +2569,17 @@ bool
 Accessible::AreItemsOperable() const
 {
   return HasOwnContent() &&
     mContent->IsElement() &&
     mContent->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::aria_activedescendant);
 }
 
 Accessible*
-Accessible::CurrentItem()
+Accessible::CurrentItem() const
 {
   // Check for aria-activedescendant, which changes which element has focus.
   // For activedescendant, the ARIA spec does not require that the user agent
   // checks whether pointed node is actually a DOM descendant of the element
   // with the aria-activedescendant attribute.
   nsAutoString id;
   if (HasOwnContent() &&
       mContent->IsElement() &&

--- a/accessible/generic/Accessible.h
+++ b/accessible/generic/Accessible.h
@@ -845,17 +845,17 @@ public:
    * can be activated.
    */
   virtual bool AreItemsOperable() const;
 
   /**
    * Return the current item of the widget, i.e. an item that has or will have
    * keyboard focus when widget gets active.
    */
-  virtual Accessible* CurrentItem();
+  virtual Accessible* CurrentItem() const;
 
   /**
    * Set the current item of the widget.
    */
   virtual void SetCurrentItem(Accessible* aItem);
 
   /**
    * Return container widget this accessible belongs to.

--- a/accessible/html/HTMLSelectAccessible.cpp
+++ b/accessible/html/HTMLSelectAccessible.cpp
@@ -88,17 +88,17 @@ HTMLSelectListAccessible::IsActiveWidget
 
 bool
 HTMLSelectListAccessible::AreItemsOperable() const
 {
   return true;
 }
 
 Accessible*
-HTMLSelectListAccessible::CurrentItem()
+HTMLSelectListAccessible::CurrentItem() const
 {
   nsIListControlFrame* listControlFrame = do_QueryFrame(GetFrame());
   if (listControlFrame) {
     nsCOMPtr<nsIContent> activeOptionNode = listControlFrame->GetCurrentOption();
     if (activeOptionNode) {
       DocAccessible* document = Document();
       if (document)
         return document->GetAccessible(activeOptionNode);
@@ -495,17 +495,17 @@ HTMLComboboxAccessible::IsActiveWidget()
 bool
 HTMLComboboxAccessible::AreItemsOperable() const
 {
   nsIComboboxControlFrame* comboboxFrame = do_QueryFrame(GetFrame());
   return comboboxFrame && comboboxFrame->IsDroppedDown();
 }
 
 Accessible*
-HTMLComboboxAccessible::CurrentItem()
+HTMLComboboxAccessible::CurrentItem() const
 {
   return AreItemsOperable() ? mListAccessible->CurrentItem() : nullptr;
 }
 
 void
 HTMLComboboxAccessible::SetCurrentItem(Accessible* aItem)
 {
   if (AreItemsOperable())

--- a/accessible/html/HTMLSelectAccessible.h
+++ b/accessible/html/HTMLSelectAccessible.h
@@ -44,17 +44,17 @@ public:
   // SelectAccessible
   virtual bool SelectAll() override;
   virtual bool UnselectAll() override;
 
   // Widgets
   virtual bool IsWidget() const override;
   virtual bool IsActiveWidget() const override;
   virtual bool AreItemsOperable() const override;
-  virtual Accessible* CurrentItem() override;
+  virtual Accessible* CurrentItem() const override;
   virtual void SetCurrentItem(Accessible* aItem) override;
 };
 
 /*
  * Options inside the select, contained within the list
  */
 class HTMLSelectOptionAccessible : public HyperTextAccessibleWrap
 {
@@ -175,17 +175,17 @@ public:
   virtual uint8_t ActionCount() override;
   virtual void ActionNameAt(uint8_t aIndex, nsAString& aName) override;
   virtual bool DoAction(uint8_t aIndex) override;
 
   // Widgets
   virtual bool IsWidget() const override;
   virtual bool IsActiveWidget() const override;
   virtual bool AreItemsOperable() const override;
-  virtual Accessible* CurrentItem() override;
+  virtual Accessible* CurrentItem() const override;
   virtual void SetCurrentItem(Accessible* aItem) override;
 
 protected:
   /**
    * Return selected option.
    */
   Accessible* SelectedOption() const;
 

--- a/accessible/xul/XULMenuAccessible.cpp
+++ b/accessible/xul/XULMenuAccessible.cpp
@@ -568,17 +568,17 @@ XULMenubarAccessible::IsActiveWidget() c
 
 bool
 XULMenubarAccessible::AreItemsOperable() const
 {
   return true;
 }
 
 Accessible*
-XULMenubarAccessible::CurrentItem()
+XULMenubarAccessible::CurrentItem() const
 {
   nsMenuBarFrame* menuBarFrame = do_QueryFrame(GetFrame());
   if (menuBarFrame) {
     nsMenuFrame* menuFrame = menuBarFrame->GetCurrentMenuItem();
     if (menuFrame) {
       nsIContent* menuItemNode = menuFrame->GetContent();
       return mDoc->GetAccessible(menuItemNode);
     }

--- a/accessible/xul/XULMenuAccessible.h
+++ b/accessible/xul/XULMenuAccessible.h
@@ -103,17 +103,17 @@ public:
   XULMenubarAccessible(nsIContent* aContent, DocAccessible* aDoc);
 
   // Accessible
   virtual a11y::role NativeRole() const override;
 
   // Widget
   virtual bool IsActiveWidget() const override;
   virtual bool AreItemsOperable() const override;
-  virtual Accessible* CurrentItem() override;
+  virtual Accessible* CurrentItem() const override;
   virtual void SetCurrentItem(Accessible* aItem) override;
 
 protected:
   // Accessible
   virtual ENameValueFlag NativeName(nsString& aName) override;
 };
 
 } // namespace a11y

--- a/accessible/xul/XULSelectControlAccessible.cpp
+++ b/accessible/xul/XULSelectControlAccessible.cpp
@@ -206,17 +206,17 @@ XULSelectControlAccessible::SelectAll()
   // otherwise, don't support this method
   return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // XULSelectControlAccessible: Widgets
 
 Accessible*
-XULSelectControlAccessible::CurrentItem()
+XULSelectControlAccessible::CurrentItem() const
 {
   if (!mSelectControl)
     return nullptr;
 
   nsCOMPtr<nsIDOMXULSelectControlItemElement> currentItemElm;
   nsCOMPtr<nsIDOMXULMultiSelectControlElement> multiSelectControl =
     do_QueryInterface(mSelectControl);
   if (multiSelectControl)

--- a/accessible/xul/XULSelectControlAccessible.h
+++ b/accessible/xul/XULSelectControlAccessible.h
@@ -31,17 +31,17 @@ public:
   virtual Accessible* GetSelectedItem(uint32_t aIndex) override;
   virtual bool IsItemSelected(uint32_t aIndex) override;
   virtual bool AddItemToSelection(uint32_t aIndex) override;
   virtual bool RemoveItemFromSelection(uint32_t aIndex) override;
   virtual bool SelectAll() override;
   virtual bool UnselectAll() override;
 
   // Widgets
-  virtual Accessible* CurrentItem() override;
+  virtual Accessible* CurrentItem() const override;
   virtual void SetCurrentItem(Accessible* aItem) override;
 
 protected:
   // nsIDOMXULMultiSelectControlElement inherits from this, so we'll always have
   // one of these if the widget is valid and not defunct
   nsCOMPtr<nsIDOMXULSelectControlElement> mSelectControl;
 };
 

--- a/accessible/xul/XULTreeAccessible.cpp
+++ b/accessible/xul/XULTreeAccessible.cpp
@@ -217,17 +217,17 @@ XULTreeAccessible::ChildAtPoint(int32_t 
 
   return child;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // XULTreeAccessible: SelectAccessible
 
 Accessible*
-XULTreeAccessible::CurrentItem()
+XULTreeAccessible::CurrentItem() const
 {
   if (!mTreeView)
     return nullptr;
 
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (selection) {
     int32_t currentIndex = -1;

--- a/accessible/xul/XULTreeAccessible.h
+++ b/accessible/xul/XULTreeAccessible.h
@@ -59,17 +59,17 @@ public:
   virtual bool RemoveItemFromSelection(uint32_t aIndex) override;
   virtual bool SelectAll() override;
   virtual bool UnselectAll() override;
 
   // Widgets
   virtual bool IsWidget() const override;
   virtual bool IsActiveWidget() const override;
   virtual bool AreItemsOperable() const override;
-  virtual Accessible* CurrentItem() override;
+  virtual Accessible* CurrentItem() const override;
   virtual void SetCurrentItem(Accessible* aItem) override;
 
   virtual Accessible* ContainerWidget() const override;
 
   // XULTreeAccessible
 
   /**
    * Return tree item accessible at the givem row. If accessible doesn't exist