Remove linked_ptr from ash

ash/first_run/desktop_cleaner.cc

 // 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.
 
 #include "ash/first_run/desktop_cleaner.h"
 
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/shell.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_observer.h"
@@ skipping 77 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(NotificationBlocker);
 };
 
 DesktopCleaner::DesktopCleaner() {
   // TODO(dzhioev): Add support for secondary displays.
   aura::Window* root_window = Shell::GetInstance()->GetPrimaryRootWindow();
   for (size_t i = 0; i < arraysize(kContainerIdsToHide); ++i) {
     aura::Window* container =
         Shell::GetContainer(root_window, kContainerIdsToHide[i]);
-    container_hiders_.push_back(make_linked_ptr(new ContainerHider(container)));
+    container_hiders_.push_back(base::MakeUnique<ContainerHider>(container));
   }
   notification_blocker_.reset(new NotificationBlocker());
 }
 
 DesktopCleaner::~DesktopCleaner() {}
 
 // static
 std::vector<int> DesktopCleaner::GetContainersToHideForTest() {
   return std::vector<int>(kContainerIdsToHide,
                           kContainerIdsToHide + arraysize(kContainerIdsToHide));
 }
 
 }  // namespace ash