We need to save bookmarks file when the persist_ids settings changes...

chrome/browser/bookmarks/bookmark_storage.h

 // Copyright (c) 2006-2008 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_BROWSER_BOOKMARKS_BOOKMARK_STORAGE_H_
 #define CHROME_BROWSER_BOOKMARKS_BOOKMARK_STORAGE_H_
 
 #include "base/file_path.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
@@ skipping 47 matching lines @@
     }
 
     BookmarkNode* bb_node() { return bb_node_.get(); }
     BookmarkNode* other_folder_node() { return other_folder_node_.get(); }
     BookmarkIndex* index() { return index_.get(); }
 
     // Max id of the nodes.
     void set_max_id(int max_id) { max_id_ = max_id; }
     int max_id() const { return max_id_; }
 
+    // Computed checksum.
+    void set_computed_checksum(const std::string& value) {
+      computed_checksum_ = value;
+    }
+    const std::string& computed_checksum() const { return computed_checksum_; }
+
+    // Stored checksum.
+    void set_stored_checksum(const std::string& value) {
+      stored_checksum_ = value;
+    }
+    const std::string& stored_checksum() const { return stored_checksum_; }
+
    private:
     scoped_ptr<BookmarkNode> bb_node_;
     scoped_ptr<BookmarkNode> other_folder_node_;
     scoped_ptr<BookmarkIndex> index_;
     int max_id_;
+    std::string computed_checksum_;
+    std::string stored_checksum_;
 
     DISALLOW_COPY_AND_ASSIGN(LoadDetails);
   };
 
   // Creates a BookmarkStorage for the specified model
   BookmarkStorage(Profile* profile, BookmarkModel* model);
   ~BookmarkStorage();
 
   // Loads the bookmarks into the model, notifying the model when done. This
   // takes ownership of |details|. See LoadDetails for details.
@@ skipping 66 matching lines @@
   // Path to temporary file created during migrating bookmarks from history.
   const FilePath tmp_history_path_;
 
   // See class description of LoadDetails for details on this.
   scoped_ptr<LoadDetails> details_;
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkStorage);
 };
 
 #endif  // CHROME_BROWSER_BOOKMARKS_BOOKMARK_STORAGE_H_