Makes sure bookmark ids are unique on reading from file. If not unique...

chrome/browser/bookmarks/bookmark_codec.h

 // Copyright (c) 2009 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.
 
 // BookmarkCodec is responsible for encoding and decoding the BookmarkModel
 // into JSON values. The encoded values are written to disk via the
 // BookmarkService.
 
 #ifndef CHROME_BROWSER_BOOKMARKS_BOOKMARK_CODEC_H_
 #define CHROME_BROWSER_BOOKMARKS_BOOKMARK_CODEC_H_
 
+#include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
 #include "base/md5.h"
 
 class BookmarkModel;
 class BookmarkNode;
 class DictionaryValue;
 class ListValue;
@@ skipping 108 matching lines @@
   void UpdateChecksumWithFolderNode(const std::string& id,
                                     const std::wstring& title);
 
   // Initializes/Finalizes the checksum.
   void InitializeChecksum();
   void FinalizeChecksum();
 
   // Whether or not IDs were reassigned by the codec.
   bool ids_reassigned_;
 
-  // Whether or not IDs were missing for some bookmark nodes during decoding.
-  bool ids_missing_;
+  // Whether or not IDs are valid. This is initially true, but set to false
+  // if an id is missing or not unique.
+  bool ids_valid_;
+
+  // Contains the id of each of the nodes found in the file. Used to determine
+  // if we have duplicates.
+  std::set<int64> ids_;
 
   // MD5 context used to compute MD5 hash of all bookmark data.
   MD5Context md5_context_;
 
   // Checksums.
   std::string computed_checksum_;
   std::string stored_checksum_;
 
   // Maximum ID assigned when decoding data.
   int64 maximum_id_;
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkCodec);
 };
 
 #endif  // CHROME_BROWSER_BOOKMARKS_BOOKMARK_CODEC_H_