[Chrome OS MD] Draw a 1px separator between 2 tray items

ash/common/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_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_H_
 #define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_H_
 
 #include <map>
 #include <memory>
 #include <vector>
@@ skipping 199 matching lines @@
 
   // Deactivate the system tray in the shelf if it was active before.
   void CloseSystemBubbleAndDeactivateSystemTray();
 
   // Records UMA metrics for the number of user-visible rows in the system menu
   // and the percentage of the work area height covered by the system menu.
   void RecordSystemMenuMetrics();
 
   const ScopedVector<SystemTrayItem>& items() const { return items_; }
 
+  // Sets an empty border around the system tray to change user-visible size
+  // of the dark background. Doesn't do anything in MD.
+  void AdjustStatusTrayBackground();
+
   // Overridden from ActionableView.
   bool PerformAction(const ui::Event& event) override;
 
   // The web notification tray view that appears adjacent to this view.
   WebNotificationTray* web_notification_tray_;
 
   // Owned items.
   ScopedVector<SystemTrayItem> items_;
 
   // Pointers to members of |items_|.
@@ skipping 32 matching lines @@
   // A reference to the Screen share and capture item.
   ScreenTrayItem* screen_capture_tray_item_;  // not owned
   ScreenTrayItem* screen_share_tray_item_;    // not owned
 
   DISALLOW_COPY_AND_ASSIGN(SystemTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_H_