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

content/browser/accessibility/browser_accessibility_manager_android.h

 // Copyright 2013 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_ANDROID_H_
 #define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
 
 #include <stdint.h>
 
 #include "base/android/scoped_java_ref.h"
@@ skipping 59 matching lines @@
   // This can be turned off to generate a tree that more accurately reflects
   // the DOM and includes style changes within these nodes.
   void set_prune_tree_for_screen_reader(bool prune) {
     prune_tree_for_screen_reader_ = prune;
   }
   bool prune_tree_for_screen_reader() { return prune_tree_for_screen_reader_; }
 
   bool ShouldExposePasswordText();
 
   // BrowserAccessibilityManager overrides.
+  BrowserAccessibility* GetFocus() override;
   void NotifyAccessibilityEvent(
       BrowserAccessibilityEvent::Source source,
       ui::AXEvent event_type,
       BrowserAccessibility* node) override;
   void SendLocationChangeEvents(
       const std::vector<AccessibilityHostMsg_LocationChangeParams>& params)
           override;
 
   // --------------------------------------------------------------------------
   // Methods called from Java via JNI
@@ skipping 166 matching lines @@
   bool prune_tree_for_screen_reader_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManagerAndroid);
 };
 
 bool RegisterBrowserAccessibilityManager(JNIEnv* env);
 
 }
 
 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_