Remove non-MD code from screen_tray_item.cc

ash/common/system/chromeos/screen_security/screen_tray_item.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_CHROMEOS_SCREEN_SECURITY_SCREEN_TRAY_ITEM_H_
 #define ASH_COMMON_SYSTEM_CHROMEOS_SCREEN_SECURITY_SCREEN_TRAY_ITEM_H_
 
 #include <string>
 
-#include "ash/common/system/tray/system_tray.h"
 #include "ash/common/system/tray/system_tray_item.h"
 #include "ash/common/system/tray/tray_item_view.h"
-#include "ash/common/system/tray/tray_notification_view.h"
 #include "base/macros.h"
 #include "ui/message_center/notification_delegate.h"
 #include "ui/views/controls/button/button.h"
-#include "ui/views/controls/image_view.h"
+#include "ui/views/view.h"
 
 namespace views {
-class View;
+class ImageView;
 }
 
 namespace ash {
 class ScreenTrayItem;
+class SystemTray;
 
 namespace tray {
 
 class ScreenTrayView : public TrayItemView {
  public:
   explicit ScreenTrayView(ScreenTrayItem* screen_tray_item);
   ~ScreenTrayView() override;
 
   void Update();
 
@@ skipping 96 matching lines @@
   tray::ScreenStatusView* default_view_;
   bool is_started_;
   base::Closure stop_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenTrayItem);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_CHROMEOS_SCREEN_SECURITY_SCREEN_TRAY_ITEM_H_