Reland of 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 25 matching lines @@
   HWND GetParentHWND();
 
   // The IAccessible for the parent window.
   IAccessible* GetParentIAccessible();
 
   // IAccessible2UsageObserver
   void OnIAccessible2Used() override;
 
   // BrowserAccessibilityManager methods
   void UserIsReloading() override;
+  BrowserAccessibility* GetFocus() override;
   void NotifyAccessibilityEvent(
       BrowserAccessibilityEvent::Source source,
       ui::AXEvent event_type,
       BrowserAccessibility* node) override;
   BrowserAccessibilityEvent::Result
       FireWinAccessibilityEvent(BrowserAccessibilityEventWin* event);
   bool CanFireEvents() override;
   void FireFocusEvent(
       BrowserAccessibilityEvent::Source source,
       BrowserAccessibility* node) override;
@@ skipping 29 matching lines @@
   // TODO(dmazzoni): a better fix would be to always have an HWND.
   // http://crbug.com/521877
   bool load_complete_pending_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManagerWin);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_WIN_H_