--- a/layout/xul/nsMenuBarListener.cpp
+++ b/layout/xul/nsMenuBarListener.cpp
@@ -35,16 +35,17 @@ NS_IMPL_ISUPPORTS(nsMenuBarListener, nsI
 int32_t nsMenuBarListener::mAccessKey = -1;
 Modifiers nsMenuBarListener::mAccessKeyMask = 0;
 bool nsMenuBarListener::mAccessKeyFocuses = false;
 
 nsMenuBarListener::nsMenuBarListener(nsMenuBarFrame* aMenuBarFrame,
                                      nsIContent* aMenuBarContent)
   : mMenuBarFrame(aMenuBarFrame)
   , mEventTarget(aMenuBarContent ? aMenuBarContent->GetComposedDoc() : nullptr)
+  , mTopWindowEventTarget(nullptr)
   , mAccessKeyDown(false)
   , mAccessKeyDownCanceled(false)
 {
   MOZ_ASSERT(mEventTarget);
 
   // Hook up the menubar as a key listener on the whole document.  This will
   // see every keypress that occurs, but after everyone else does.
 
@@ -61,16 +62,24 @@ nsMenuBarListener::nsMenuBarListener(nsM
 
   // mousedown event should be handled in all phase
   mEventTarget->AddEventListener(NS_LITERAL_STRING("mousedown"), this, true);
   mEventTarget->AddEventListener(NS_LITERAL_STRING("mousedown"), this, false);
   mEventTarget->AddEventListener(NS_LITERAL_STRING("blur"), this, true);
 
   mEventTarget->AddEventListener(
                   NS_LITERAL_STRING("MozDOMFullscreen:Entered"), this, false);
+
+  // Needs to listen to the deactivate event of the window.
+  RefPtr<EventTarget> topWindowEventTarget =
+    nsContentUtils::GetWindowRoot(aMenuBarContent->GetComposedDoc());
+  mTopWindowEventTarget = topWindowEventTarget.get();
+
+  mTopWindowEventTarget->AddSystemEventListener(NS_LITERAL_STRING("deactivate"),
+                                                this, true);
 }
 
 ////////////////////////////////////////////////////////////////////////
 nsMenuBarListener::~nsMenuBarListener() 
 {
   MOZ_ASSERT(!mEventTarget,
              "OnDestroyMenuBarFrame() should've alreay been called");
 }
@@ -90,18 +99,22 @@ nsMenuBarListener::OnDestroyMenuBarFrame
   mEventTarget->RemoveEventListener(NS_LITERAL_STRING("mousedown"), this, true);
   mEventTarget->RemoveEventListener(NS_LITERAL_STRING("mousedown"),
                                     this, false);
   mEventTarget->RemoveEventListener(NS_LITERAL_STRING("blur"), this, true);
 
   mEventTarget->RemoveEventListener(
                   NS_LITERAL_STRING("MozDOMFullscreen:Entered"), this, false);
 
+  mTopWindowEventTarget->RemoveSystemEventListener(
+                           NS_LITERAL_STRING("deactivate"), this, true);
+
   mMenuBarFrame = nullptr;
   mEventTarget = nullptr;
+  mTopWindowEventTarget = nullptr;
 }
 
 void
 nsMenuBarListener::InitializeStatics()
 {
   Preferences::AddBoolVarCache(&mAccessKeyFocuses,
                                "ui.key.menuAccessKeyFocuses");
 }
@@ -410,24 +423,34 @@ nsMenuBarListener::KeyDown(nsIDOMEvent* 
 
 ////////////////////////////////////////////////////////////////////////
 
 nsresult
 nsMenuBarListener::Blur(nsIDOMEvent* aEvent)
 {
   if (!mMenuBarFrame->IsMenuOpen() && mMenuBarFrame->IsActive()) {
     ToggleMenuActiveState();
+    mAccessKeyDown = false;
+    mAccessKeyDownCanceled = false;
   }
+  return NS_OK; // means I am NOT consuming event
+}
+
+////////////////////////////////////////////////////////////////////////
+
+nsresult
+nsMenuBarListener::OnWindowDeactivated(nsIDOMEvent* aEvent)
+{
   // Reset the accesskey state because we cannot receive the keyup event for
   // the pressing accesskey.
   mAccessKeyDown = false;
   mAccessKeyDownCanceled = false;
   return NS_OK; // means I am NOT consuming event
 }
-  
+
 ////////////////////////////////////////////////////////////////////////
 nsresult 
 nsMenuBarListener::MouseDown(nsIDOMEvent* aMouseEvent)
 {
   // NOTE: MouseDown method listens all phases
 
   // Even if the mousedown event is canceled, it means the user don't want
   // to activate the menu.  Therefore, we need to record it at capturing (or
@@ -483,16 +506,19 @@ nsMenuBarListener::HandleEvent(nsIDOMEve
     return KeyPress(aEvent);
   }
   if (eventType.EqualsLiteral("mozaccesskeynotfound")) {
     return KeyPress(aEvent);
   }
   if (eventType.EqualsLiteral("blur")) {
     return Blur(aEvent);
   }
+  if (eventType.EqualsLiteral("deactivate")) {
+    return OnWindowDeactivated(aEvent);
+  }
   if (eventType.EqualsLiteral("mousedown")) {
     return MouseDown(aEvent);
   }
   if (eventType.EqualsLiteral("MozDOMFullscreen:Entered")) {
     return Fullscreen(aEvent);
   }
 
   NS_ABORT();

--- a/layout/xul/nsMenuBarListener.h
+++ b/layout/xul/nsMenuBarListener.h
@@ -60,16 +60,17 @@ public:
 
 protected:
   virtual ~nsMenuBarListener();
 
   nsresult KeyUp(nsIDOMEvent* aMouseEvent);
   nsresult KeyDown(nsIDOMEvent* aMouseEvent);
   nsresult KeyPress(nsIDOMEvent* aMouseEvent);
   nsresult Blur(nsIDOMEvent* aEvent);
+  nsresult OnWindowDeactivated(nsIDOMEvent* aEvent);
   nsresult MouseDown(nsIDOMEvent* aMouseEvent);
   nsresult Fullscreen(nsIDOMEvent* aEvent);
 
   static void InitAccessKey();
 
   static mozilla::Modifiers GetModifiersForAccessKey(nsIDOMKeyEvent* event);
 
   // This should only be called by the nsMenuBarListener during event dispatch,
@@ -80,16 +81,18 @@ protected:
 
   // The menu bar object.
   nsMenuBarFrame* mMenuBarFrame;
   // The event target to listen to the events.
   // XXX Should this store this as strong reference?  However,
   //     OnDestroyMenuBarFrame() should be called at destroying mMenuBarFrame.
   //     So, weak reference must be safe.
   mozilla::dom::EventTarget* mEventTarget;
+  // The top window as EventTarget.
+  mozilla::dom::EventTarget* mTopWindowEventTarget;
   // Whether or not the ALT key is currently down.
   bool mAccessKeyDown;
   // Whether or not the ALT key down is canceled by other action.
   bool mAccessKeyDownCanceled;
   // Does the access key by itself focus the menubar?
   static bool mAccessKeyFocuses;
   // See nsIDOMKeyEvent.h for sample values.
   static int32_t mAccessKey;