Add old_state parameter to CustomButton::StateChanged

ash/common/system/tray/tray_popup_header_button.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 ASH_COMMON_SYSTEM_TRAY_TRAY_POPUP_HEADER_BUTTON_H_
 #define ASH_COMMON_SYSTEM_TRAY_TRAY_POPUP_HEADER_BUTTON_H_
 
 #include "ash/ash_export.h"
 #include "base/macros.h"
 #include "ui/views/controls/button/image_button.h"
@@ skipping 16 matching lines @@
                         int disabled_resource_id_hover,
                         int accessible_name_id);
   ~TrayPopupHeaderButton() override;
 
  private:
   // Overridden from views::View:
   const char* GetClassName() const override;
   gfx::Size GetPreferredSize() const override;
 
   // Overridden from views::CustomButton:
-  void StateChanged() override;
+  void StateChanged(ButtonState old_state) override;
 
   void Initialize(const gfx::ImageSkia& icon, int accessible_name_id);
 
   DISALLOW_COPY_AND_ASSIGN(TrayPopupHeaderButton);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_TRAY_POPUP_HEADER_BUTTON_H_