ash uber tray: Make the tray background rounded.

ash/system/tray/system_tray.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_SYSTEM_TRAY_H_
 #define ASH_SYSTEM_TRAY_SYSTEM_TRAY_H_
 #pragma once
 
 #include "ash/ash_export.h"
 #include "ash/system/user/login_status.h"
@@ skipping 30 matching lines @@
   // Updates the items when the login status of the system changes.
   void UpdateAfterLoginStatusChange(user::LoginStatus login_status);
 
   const std::vector<SystemTrayItem*>& items() const { return items_; }
 
  private:
   void ShowItems(std::vector<SystemTrayItem*>& items, bool details);
 
   // Overridden from views::View.
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
+  virtual void OnMouseEntered(const views::MouseEvent& event) OVERRIDE;
+  virtual void OnMouseExited(const views::MouseEvent& event) OVERRIDE;
 
   // Overridden from views::Widget::Observer.
   virtual void OnWidgetClosing(views::Widget* widget) OVERRIDE;
 
   std::vector<SystemTrayItem*> items_;
 
   // The popup widget and the delegate.
   internal::SystemTrayBubble* bubble_;
   views::Widget* popup_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_SYSTEM_TRAY_H_