--- a/accessible/ipc/DocAccessibleChild.cpp
+++ b/accessible/ipc/DocAccessibleChild.cpp
@@ -1648,16 +1648,34 @@ DocAccessibleChild::RecvEmbeddedChildAt(
   if (!acc)
     return true;
 
   *aChildID = reinterpret_cast<uintptr_t>(acc->GetEmbeddedChildAt(aIdx));
   return true;
 }
 
 bool
+DocAccessibleChild::RecvFocusedChild(const uint64_t& aID,
+                                       uint64_t* aChild,
+                                       bool* aOk)
+{
+  *aChild = 0;
+  *aOk = false;
+  Accessible* acc = IdToAccessible(aID);
+  if (acc) {
+    Accessible* child = acc->FocusedChild();
+    if (child) {
+      *aChild = reinterpret_cast<uint64_t>(child->UniqueID());
+      *aOk = true;
+    }
+  }
+  return true;
+}
+
+bool
 DocAccessibleChild::RecvChildAtPoint(const uint64_t& aID,
                                      const int32_t& aX,
                                      const int32_t& aY,
                                      const uint32_t& aWhich,
                                      uint64_t* aChild,
                                      bool* aOk)
 {
   *aChild = 0;

--- a/accessible/ipc/DocAccessibleChild.h
+++ b/accessible/ipc/DocAccessibleChild.h
@@ -406,16 +406,20 @@ public:
 
   virtual bool RecvIndexOfEmbeddedChild(const uint64_t& aID,
                                         const uint64_t& aChildID,
                                         uint32_t* aChildIdx) override final;
 
   virtual bool RecvEmbeddedChildAt(const uint64_t& aID, const uint32_t& aIdx,
                                    uint64_t* aChildID) override final;
 
+  virtual bool RecvFocusedChild(const uint64_t& aID,
+                                uint64_t* aChild,
+                                bool* aOk) override;
+
   virtual bool RecvChildAtPoint(const uint64_t& aID,
                                 const int32_t& aX,
                                 const int32_t& aY,
                                 const uint32_t& aWhich,
                                 uint64_t* aChild,
                                 bool* aOk) override;
 
   virtual bool RecvBounds(const uint64_t& aID, nsIntRect* aRect) override;

--- a/accessible/ipc/PDocAccessible.ipdl
+++ b/accessible/ipc/PDocAccessible.ipdl
@@ -217,16 +217,18 @@ child:
   prio(high) sync MaxValue(uint64_t aID) returns(double aValue);
   prio(high) sync Step(uint64_t aID) returns(double aStep);
 
   prio(high) sync TakeFocus(uint64_t aID);
   prio(high) sync IndexOfEmbeddedChild(uint64_t aID, uint64_t aChildID)
     returns(uint32_t childIdx);
   prio(high) sync EmbeddedChildAt(uint64_t aID, uint32_t aChildIdx)
     returns(uint64_t aChild);
+  prio(high) sync FocusedChild(uint64_t aID)
+    returns(uint64_t aChild, bool aOk);
   prio(high) sync ChildAtPoint(uint64_t aID, int32_t aX, int32_t aY, uint32_t aWhich)
     returns(uint64_t aChild, bool aOk);
   prio(high) sync Bounds(uint64_t aID) returns(nsIntRect aRect);
 
   prio(high) sync Language(uint64_t aID) returns(nsString aLocale);
   prio(high) sync DocType(uint64_t aID) returns(nsString aType);
   prio(high) sync URL(uint64_t aID) returns(nsString aURL);
   prio(high) sync MimeType(uint64_t aID) returns(nsString aMime);

--- a/accessible/ipc/ProxyAccessible.cpp
+++ b/accessible/ipc/ProxyAccessible.cpp
@@ -920,16 +920,25 @@ ProxyAccessible*
 ProxyAccessible::EmbeddedChildAt(size_t aChildIdx)
 {
   uint64_t childID;
   unused << mDoc->SendEmbeddedChildAt(mID, aChildIdx, &childID);
   return mDoc->GetAccessible(childID);
 }
 
 ProxyAccessible*
+ProxyAccessible::FocusedChild()
+{
+  uint64_t childID = 0;
+  bool ok = false;
+  unused << mDoc->SendFocusedChild(mID, &childID, &ok);
+  return ok ? mDoc->GetAccessible(childID) : nullptr;
+}
+
+ProxyAccessible*
 ProxyAccessible::ChildAtPoint(int32_t aX, int32_t aY,
                               Accessible::EWhichChildAtPoint aWhichChild)
 {
   uint64_t childID = 0;
   bool ok = false;
   unused << mDoc->SendChildAtPoint(mID, aX, aY,
                                    static_cast<uint32_t>(aWhichChild),
                                    &childID, &ok);

--- a/accessible/ipc/ProxyAccessible.h
+++ b/accessible/ipc/ProxyAccessible.h
@@ -272,16 +272,17 @@ public:
 
   double CurValue();
   bool SetCurValue(double aValue);
   double MinValue();
   double MaxValue();
   double Step();
 
   void TakeFocus();
+  ProxyAccessible* FocusedChild();
   ProxyAccessible* ChildAtPoint(int32_t aX, int32_t aY,
                                 Accessible::EWhichChildAtPoint aWhichChild);
   nsIntRect Bounds();
 
   void Language(nsString& aLocale);
   void DocType(nsString& aType);
   void URL(nsString& aURL);
   void MimeType(nsString aMime);