Add best-effort/allow rollback flags on WorkItem.

chrome/installer/util/delete_tree_work_item.h

 // Copyright (c) 2011 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_INSTALLER_UTIL_DELETE_TREE_WORK_ITEM_H_
 #define CHROME_INSTALLER_UTIL_DELETE_TREE_WORK_ITEM_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "chrome/installer/util/work_item.h"
 
 // A WorkItem subclass that recursively deletes a file system hierarchy at the
 // given root path. The file system hierarchy could be a single file, or a
 // directory.
 // The file system hierarchy to be deleted can have one or more key files. If
 // specified, deletion will be performed only if all key files are not in use.
 class DeleteTreeWorkItem : public WorkItem {
  public:
   ~DeleteTreeWorkItem() override;
 
-  bool Do() override;
-
-  void Rollback() override;
-
  private:
   friend class WorkItem;
 
   // |root_path| will be moved to |temp_path| (rather than copied there and then
   // deleted). For best results in this case, |root_path| and |temp_path|
   // should be on the same volume; otherwise, the move will be simulated
   // by a copy-and-delete operation.
   DeleteTreeWorkItem(const base::FilePath& root_path,
                      const base::FilePath& temp_path,
                      const std::vector<base::FilePath>& key_paths);

[fdoray, 2016/05/02 20:10:01]

|key_paths| is always empty. Can I remove the argument and all associated code?

[grt (UTC plus 2), 2016/05/06 18:39:13]

That'd be great. Unused code is just weight. We can add it back from history in
the future if needed.

[fdoray, 2016/05/10 18:35:28]

Done.

 
+  // WorkItem:
+  bool DoImpl() override;
+  void RollbackImpl() override;
+
   // Return temporary path for work based on |backup_path_| and |root_path_|.
   base::FilePath GetBackupPath();
 
   // Attempts to delete |root_path_|. Returns true on success.
   bool DeleteRoot();
 
   // Attempts to move |root_path_| to backup. Returns true on success.
   bool MoveRootToBackup();
 
   // Root path to delete.
@@ skipping 15 matching lines @@
   std::unique_ptr<base::ScopedTempDir[]> key_backup_paths_;
 
   // The temporary directory into which the original root_path_ has been moved.
   base::ScopedTempDir backup_path_;
 
   // Set to true once root_path_ has been moved into backup_path_.
   bool moved_to_backup_;
 };
 
 #endif  // CHROME_INSTALLER_UTIL_DELETE_TREE_WORK_ITEM_H_