Supporting undoing bookmark deletion without creating new ID.

components/bookmarks/browser/bookmark_undo_delegate.h

+// Copyright 2015 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 COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_UNDO_DELEGATE_H_
+#define COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_UNDO_DELEGATE_H_
+
+#include "base/memory/scoped_ptr.h"
+
+namespace bookmarks {
+
+class BookmarkModel;
+class BookmarkNode;
+class BookmarkUndoProvider;
+
+// Delegate to handle bookmark change events in order to support undo when
+// requested.
+class BookmarkUndoDelegate {
+ public:
+  virtual ~BookmarkUndoDelegate() {}
+
+  // Sets the provider that will do the undo work.
+  virtual void SetUndoProvider(BookmarkUndoProvider* provider) = 0;
+
+  // Called when |node| was removed from |parent| at position |index|.
+  virtual void OnBookmarkNodeRemoved(BookmarkModel* model,
+                                     const BookmarkNode* parent,
+                                     int index,
+                                     scoped_ptr<BookmarkNode> node) = 0;
+};
+
+
+}  // namespace bookmarks
+
+#endif  // COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_UNDO_DELEGATE_H_