Uses the activedescendant_changed event received from Blink to fire the right focus event

content/browser/accessibility/browser_accessibility_manager_win.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_WIN_H_
 #define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_WIN_H_
 
 #include <oleacc.h>
 
 #include <memory>
@@ skipping 27 matching lines @@
   IAccessible* GetParentIAccessible();
 
   // Calls NotifyWinEvent if the parent window's IAccessible pointer is known.
   void MaybeCallNotifyWinEvent(DWORD event, BrowserAccessibility* node);
 
   // IAccessible2UsageObserver
   void OnIAccessible2Used() override;
 
   // BrowserAccessibilityManager methods
   void UserIsReloading() override;
+  BrowserAccessibility* GetFocus() override;
   void NotifyAccessibilityEvent(
       ui::AXEvent event_type, BrowserAccessibility* node) override;
   bool CanFireEvents() override;
   void FireFocusEvent(BrowserAccessibility* node) override;
 
   // Track this object and post a VISIBLE_DATA_CHANGED notification when
   // its container scrolls.
   // TODO(dmazzoni): remove once http://crbug.com/113483 is fixed.
   void TrackScrollingObject(BrowserAccessibilityWin* node);
 
@@ skipping 17 matching lines @@
   // post a notification directly on it when it reaches its destination.
   // TODO(dmazzoni): remove once http://crbug.com/113483 is fixed.
   BrowserAccessibilityWin* tracked_scroll_object_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManagerWin);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_WIN_H_