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

ash/common/system/status_area_widget.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_STATUS_AREA_WIDGET_H_
 #define ASH_COMMON_SYSTEM_STATUS_AREA_WIDGET_H_
 
 #include "ash/ash_export.h"
 #include "ash/common/login_status.h"
 #include "ash/common/shelf/shelf_background_animator_observer.h"
 #include "ash/common/shelf/shelf_types.h"
 #include "base/macros.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
 class OverviewButtonTray;
 class ShellDelegate;
 class StatusAreaWidgetDelegate;
 class SystemTray;
+class TrayBackgroundView;
 class WebNotificationTray;
 class WmShelf;
 class WmWindow;
 #if defined(OS_CHROMEOS)
 class ImeMenuTray;
 class LogoutButtonTray;
 class PaletteTray;
 class VirtualKeyboardTray;
 #endif
 
@@ skipping 11 matching lines @@
   void Shutdown();
 
   // Update the alignment of the widget and tray views.
   void SetShelfAlignment(ShelfAlignment alignment);
 
   // Called by the client when the login status changes. Caches login_status
   // and calls UpdateAfterLoginStatusChange for the system tray and the web
   // notification tray.
   void UpdateAfterLoginStatusChange(LoginStatus login_status);
 
+  // Based on visibility of |tray| and a tray item on its right, sets |tray|'s
+  // separator visibility either to true or false. Note that no leading
+  // separator is required before the logout_button_tray because that
+  // button's red background is distinctive on its own.
+  void OnTrayVisibilityChanged(TrayBackgroundView* tray);
+
   StatusAreaWidgetDelegate* status_area_widget_delegate() {
     return status_area_widget_delegate_;
   }
   SystemTray* system_tray() { return system_tray_; }
   WebNotificationTray* web_notification_tray() {
     return web_notification_tray_;
   }
   OverviewButtonTray* overview_button_tray() { return overview_button_tray_; }
 
 #if defined(OS_CHROMEOS)
@@ skipping 23 matching lines @@
   void UpdateShelfItemBackground(int alpha) override;
 
  private:
   void AddSystemTray();
   void AddWebNotificationTray();
 #if defined(OS_CHROMEOS)
   void AddLogoutButtonTray();
   void AddPaletteTray();
   void AddVirtualKeyboardTray();
   void AddImeMenuTray();
+
+  // Checks if |tray| is the next visible tray to the left of
+  // |logout_button_tray_|. Returns true if both are visible, false otherwise.
+  bool IsNextVisibleTrayToLogout(TrayBackgroundView* tray) const;
 #endif
   void AddOverviewButtonTray();
 
   // Weak pointers to View classes that are parented to StatusAreaWidget:
   StatusAreaWidgetDelegate* status_area_widget_delegate_;
   OverviewButtonTray* overview_button_tray_;
   SystemTray* system_tray_;
   WebNotificationTray* web_notification_tray_;
 #if defined(OS_CHROMEOS)
   LogoutButtonTray* logout_button_tray_;
   PaletteTray* palette_tray_;
   VirtualKeyboardTray* virtual_keyboard_tray_;
   ImeMenuTray* ime_menu_tray_;
 #endif
   LoginStatus login_status_;
 
   WmShelf* wm_shelf_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusAreaWidget);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_STATUS_AREA_WIDGET_H_