Try the original CL "Always persist bookmark IDs" again with the fix to...

chrome/browser/bookmarks/bookmark_codec.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.
 
 // 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;
 class Value;
 
-// Utility class to help assign unique integer IDs.
+// Utility class to help assign unique 64-bit IDs.
 class UniqueIDGenerator {
  public:
   UniqueIDGenerator();
 
   // Checks whether the given ID can be used as a unique ID or not. If it can,
   // returns the id itself, otherwise generates a new unique id in a simple way
   // and returns that.
   // NOTE that if id is 0, a new unique id is returned.
-  int GetUniqueID(int id);
+  int64 GetUniqueID(int64 id);
 
   // Resets the ID generator to initial state.
   void Reset();
 
   // Returns the current maximum.
-  int current_max() const { return current_max_; }
+  int64 current_max() const { return current_max_; }
 
  private:
   // Checks if the given ID is already assigned.
-  bool IsIdAssigned(int id) const;
+  bool IsIdAssigned(int64 id) const;
 
   // Records the given ID as assigned.
-  void RecordId(int id);
+  void RecordId(int64 id);
 
   // Maximum value we have seen so far.
-  int current_max_;
+  int64 current_max_;
+
   // All IDs assigned so far.
-  scoped_ptr<std::set<int> > assigned_ids_;
+  scoped_ptr<std::set<int64> > assigned_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(UniqueIDGenerator);
 };
 
 // BookmarkCodec is responsible for encoding/decoding bookmarks into JSON
 // values. BookmarkCodec is used by BookmarkService.
 
 class BookmarkCodec {
  public:
-  // Creates an instance of the codec. Encodes/decodes bookmark IDs also if
-  // persist_ids is true. The default constructor will not encode/decode IDs.
-  // During decoding, if persist_ids is true and if the IDs in the file are not
-  // unique, we will reassign IDs to make them unique. There are no guarantees
-  // on how the IDs are reassigned or about doing minimal reassignments to
-  // achieve uniqueness.
+  // Creates an instance of the codec. During decoding, if the IDs in the file
+  // are not unique, we will reassign IDs to make them unique. There are no
+  // guarantees on how the IDs are reassigned or about doing minimal
+  // reassignments to achieve uniqueness.
   BookmarkCodec();
-  explicit BookmarkCodec(bool persist_ids);
 
   // Encodes the model to a JSON value. It's up to the caller to delete the
   // returned object. This is invoked to encode the contents of the bookmark bar
   // model and is currently a convenience to invoking Encode that takes the
   // bookmark bar node and other folder node.
   Value* Encode(BookmarkModel* model);
 
   // Encodes the bookmark bar and other folders returning the JSON value. It's
   // up to the caller to delete the returned object.
   // This method is public for use by StarredURLDatabase in migrating the
   // bookmarks out of the database.
   Value* Encode(const BookmarkNode* bookmark_bar_node,
                 const BookmarkNode* other_folder_node);
 
   // Decodes the previously encoded value to the specified nodes as well as
   // setting |max_node_id| to the greatest node id. Returns true on success,
   // false otherwise. If there is an error (such as unexpected version) all
   // children are removed from the bookmark bar and other folder nodes. On exit
   // |max_node_id| is set to the max id of the nodes.
   bool Decode(BookmarkNode* bb_node,
               BookmarkNode* other_folder_node,
-              int* max_node_id,
+              int64* max_node_id,
               const Value& value);
 
   // Returns the checksum computed during last encoding/decoding call.
   const std::string& computed_checksum() const { return computed_checksum_; }
 
   // Returns the checksum that's stored in the file. After a call to Encode,
   // the computed and stored checksums are the same since the computed checksum
   // is stored to the file. After a call to decode, the computed checksum can
   // differ from the stored checksum if the file contents were changed by the
   // user.
   const std::string& stored_checksum() const { return stored_checksum_; }
 
+  // Returns whether the IDs were reassigned during decoding. Always returns
+  // false after encoding.
+  bool ids_reassigned() const { return ids_reassigned_; }
+
   // Names of the various keys written to the Value.
   static const wchar_t* kRootsKey;
   static const wchar_t* kRootFolderNameKey;
   static const wchar_t* kOtherBookmarkFolderNameKey;
   static const wchar_t* kVersionKey;
   static const wchar_t* kChecksumKey;
   static const wchar_t* kIdKey;
   static const wchar_t* kTypeKey;
   static const wchar_t* kNameKey;
   static const wchar_t* kDateAddedKey;
   static const wchar_t* kURLKey;
   static const wchar_t* kDateModifiedKey;
   static const wchar_t* kChildrenKey;
 
   // Possible values for kTypeKey.
   static const wchar_t* kTypeURL;
   static const wchar_t* kTypeFolder;
 
  private:
   // Encodes node and all its children into a Value object and returns it.
   // The caller takes ownership of the returned object.
   Value* EncodeNode(const BookmarkNode* node);
 
   // Helper to perform decoding.
   bool DecodeHelper(BookmarkNode* bb_node,
                     BookmarkNode* other_folder_node,
-                    int* max_id,
                     const Value& value);
 
   // Decodes the children of the specified node. Returns true on success.
   bool DecodeChildren(const ListValue& child_value_list,
                       BookmarkNode* parent);
 
   // Decodes the supplied node from the supplied value. Child nodes are
   // created appropriately by way of DecodeChildren. If node is NULL a new
   // node is created and added to parent, otherwise node is used.
   bool DecodeNode(const DictionaryValue& value,
@@ skipping 12 matching lines @@
   void UpdateChecksumWithUrlNode(const std::string& id,
                                  const std::wstring& title,
                                  const std::wstring& url);
   void UpdateChecksumWithFolderNode(const std::string& id,
                                     const std::wstring& title);
 
   // Initializes/Finalizes the checksum.
   void InitializeChecksum();
   void FinalizeChecksum();
 
-  // Whether to persist IDs or not.
-  bool persist_ids_;
   // Unique ID generator used during decoding.
   UniqueIDGenerator id_generator_;
 
+  // Whether or not IDs were reassigned by the codec.
+  bool ids_reassigned_;
+
   // MD5 context used to compute MD5 hash of all bookmark data.
   MD5Context md5_context_;
 
   // Checksums.
   std::string computed_checksum_;
   std::string stored_checksum_;
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkCodec);
 };
 
 #endif  // CHROME_BROWSER_BOOKMARKS_BOOKMARK_CODEC_H_