ash: Make the buttons in the tray-popup headers accessible from keyboard.

ash/system/tray/tray_views.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 ASH_SYSTEM_TRAY_TRAY_VIEWS_H_
 #define ASH_SYSTEM_TRAY_TRAY_VIEWS_H_
 #pragma once
 
 #include "ui/gfx/font.h"
 #include "ui/gfx/size.h"
@@ skipping 173 matching lines @@
  public:
   TrayPopupHeaderButton(views::ButtonListener* listener,
                         int enabled_resource_id,
                         int disabled_resource_id);
   virtual ~TrayPopupHeaderButton();
 
  private:
   // Overridden from views::View.
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual void OnPaintBorder(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaintFocusBorder(gfx::Canvas* canvas) OVERRIDE;
 
   // Overridden from views::CustomButton.
   virtual void StateChanged() OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(TrayPopupHeaderButton);
 };
 
 // Creates a container for the various detailed popups. Clicking on the view
 // triggers the callback in ViewClickListener.
 views::View* CreateDetailedHeaderEntry(int string_id,
                                        ViewClickListener* listener);
 
 // Sets up a Label properly for the tray (sets color, font etc.).
 void SetupLabelForTray(views::Label* label);
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_TRAY_VIEWS_H_