Revert of Some linked_ptr removal in chromeos file_browser_handler.

chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc

 // 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.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
@@ skipping 306 matching lines @@
       browser()->profile());
 
   // Add a provided file system, to test passing the |configurable| and
   // |source| flags properly down to Files app.
   chromeos::file_system_provider::ProvidedFileSystemInfo info(
       "testing-extension-id", chromeos::file_system_provider::MountOptions(),
       base::FilePath(), true /* configurable */, false /* watchable */,
       extensions::SOURCE_NETWORK);
 
   file_manager::VolumeManager::Get(browser()->profile())
-      ->AddVolumeForTesting(file_manager::Volume::CreateForProvidedFileSystem(
-          info, file_manager::MOUNT_CONTEXT_AUTO));
+      ->AddVolumeForTesting(
+          make_linked_ptr(file_manager::Volume::CreateForProvidedFileSystem(
+              info, file_manager::MOUNT_CONTEXT_AUTO)));
 
   // We will call fileManagerPrivate.unmountVolume once. To test that method, we
   // check that UnmountPath is really called with the same value.
   EXPECT_CALL(*disk_mount_manager_mock_, UnmountPath(_, _, _))
       .Times(0);
   EXPECT_CALL(*disk_mount_manager_mock_,
               UnmountPath(
                   chromeos::CrosDisksClient::GetArchiveMountPoint().AppendASCII(
                       "archive_mount_path").AsUTF8Unsafe(),
                   chromeos::UNMOUNT_OPTIONS_NONE, _)).Times(1);
@@ skipping 100 matching lines @@
                   ->RegisterFileSystem(
                       kLocalMountPointName, storage::kFileSystemTypeNativeLocal,
                       storage::FileSystemMountOption(), mount_point_dir));
   file_manager::VolumeManager::Get(browser()->profile())
       ->AddVolumeForTesting(mount_point_dir, file_manager::VOLUME_TYPE_TESTING,
                             chromeos::DEVICE_TYPE_UNKNOWN,
                             false /* read_only */);
 
   ASSERT_TRUE(RunComponentExtensionTest("file_browser/content_checksum_test"));
 }