Support undoing offline page deletion

components/bookmarks/browser/bookmark_model_observer.h

Index: components/bookmarks/browser/bookmark_model_observer.h
diff --git a/components/bookmarks/browser/bookmark_model_observer.h b/components/bookmarks/browser/bookmark_model_observer.h
index a946d532ac8cdcf21053944e7d0b9e3d7bbea994..ad1fd9e7c361429c1819b9b6761f8cf85fa5767a 100644
--- a/components/bookmarks/browser/bookmark_model_observer.h
+++ b/components/bookmarks/browser/bookmark_model_observer.h
@@ -7,6 +7,8 @@
 
 #include <set>
 
+#include "base/basictypes.h"
+
 class GURL;
 
 namespace bookmarks {
@@ -134,6 +136,14 @@ class BookmarkModelObserver {
   // 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() {}
 };