Use OnceCallback on Mojo interfaces in //ash

chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.h

 // Copyright (c) 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 CHROME_BROWSER_UI_ASH_LAUNCHER_BROWSER_SHORTCUT_LAUNCHER_ITEM_CONTROLLER_H_
 #define CHROME_BROWSER_UI_ASH_LAUNCHER_BROWSER_SHORTCUT_LAUNCHER_ITEM_CONTROLLER_H_
 
 #include "ash/public/cpp/shelf_item_delegate.h"
 #include "base/macros.h"
 #include "chrome/browser/ui/browser_list.h"
@@ skipping 25 matching lines @@
   void SetShelfIDForBrowserWindowContents(Browser* browser,
                                           content::WebContents* web_contents);
 
   // Check if there is any active browsers windows.
   bool IsListOfActiveBrowserEmpty();
 
   // ash::ShelfItemDelegate overrides:
   void ItemSelected(std::unique_ptr<ui::Event> event,
                     int64_t display_id,
                     ash::ShelfLaunchSource source,
-                    const ItemSelectedCallback& callback) override;
+                    ItemSelectedCallback callback) override;
   ash::MenuItemList GetAppMenuItems(int event_flags) override;
   void ExecuteCommand(uint32_t command_id, int32_t event_flags) override;
   void Close() override;
 
  private:
   // Activate a browser - or advance to the next one on the list.
   // Returns the action performed. Should be one of SHELF_ACTION_NONE,
   // SHELF_ACTION_WINDOW_ACTIVATED, or SHELF_ACTION_NEW_WINDOW_CREATED.
   ash::ShelfAction ActivateOrAdvanceToNextBrowser();
 
@@ skipping 14 matching lines @@
   // The cached list of open browser windows shown in an application menu.
   BrowserList::BrowserVector browser_menu_items_;
 
   // Registers for notifications of closing browser windows.
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserShortcutLauncherItemController);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_LAUNCHER_BROWSER_SHORTCUT_LAUNCHER_ITEM_CONTROLLER_H_