Update focus when widget changes visibility.

ui/views/accessibility/ax_widget_obj_wrapper.h

 // Copyright 2014 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 UI_VIEWS_ACCESSIBILITY_AX_WIDGET_OBJ_WRAPPER_H_
 #define UI_VIEWS_ACCESSIBILITY_AX_WIDGET_OBJ_WRAPPER_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
@@ skipping 14 matching lines @@
 
   // AXAuraObjWrapper overrides.
   AXAuraObjWrapper* GetParent() override;
   void GetChildren(std::vector<AXAuraObjWrapper*>* out_children) override;
   void Serialize(ui::AXNodeData* out_node_data) override;
   int32_t GetID() override;
 
   // WidgetObserver overrides.
   void OnWidgetDestroying(Widget* widget) override;
   void OnWidgetClosing(Widget* widget) override;
+  void OnWidgetVisibilityChanged(Widget*, bool) override;
 
   // WidgetRemovalsObserver overrides.
   void OnWillRemoveView(Widget* widget, View* view) override;
 
  private:
   Widget* widget_;
 
   DISALLOW_COPY_AND_ASSIGN(AXWidgetObjWrapper);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ACCESSIBILITY_AX_WIDGET_OBJ_WRAPPER_H_