Support undoing offline page deletion

components/bookmarks/browser/bookmark_model_observer.h

 // Copyright 2014 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_MODEL_OBSERVER_H_
 #define COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_MODEL_OBSERVER_H_
 
 #include <set>
 
+#include "base/basictypes.h"
+
 class GURL;
 
 namespace bookmarks {
 
 class BookmarkModel;
 class BookmarkNode;
 
 // Observer for the BookmarkModel.
 class BookmarkModelObserver {
  public:
@@ skipping 107 matching lines @@
 
   // Invoked before a set of model changes that is initiated by a single user
   // action. For example, this is called a single time when pasting from the
   // clipboard before each pasted bookmark is added to the bookmark model.
   virtual void GroupedBookmarkChangesBeginning(BookmarkModel* model) {}
 
   // Invoked after a set of model changes triggered by a single user action has
   // ended.
   virtual void GroupedBookmarkChangesEnded(BookmarkModel* model) {}
 
+  // Invoked after the bookmark deletion is undo-ed that caused a new bookmark
+  // with new_id being created and cloned from the deleted bookmark with old_id.
+  // This event is needed to support restoring other data that is associated
+  // with bookmark but stored separately, like offline page data.
+  // occurs.
+  virtual void BookmarkNodeRenumbered(
+      BookmarkModel* model, int64_t old_id, int64_t new_id) {}
+
  protected:
   virtual ~BookmarkModelObserver() {}
 };
 
 }  // namespace bookmarks
 
 #endif  // COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_MODEL_OBSERVER_H_