sync: Start moving away from PREV_ID and NEXT_ID

sync/engine/conflict_resolver.cc

 // Copyright 2012 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.
 
 #include "sync/engine/conflict_resolver.h"
 
 #include <list>
 #include <set>
 #include <string>
 
@@ skipping 122 matching lines @@
     // same are supported due to the predecessor->successor ordering. In this
     // case, from the first item onward, we unset the UNSYNCED/UNAPPLIED bits as
     // we decide that nothing changed. The subsequent item's server prev id will
     // accurately match the local prev id because the predecessor is no longer
     // UNSYNCED/UNAPPLIED.
     // TODO(zea): simplify all this once we can directly compare server position
     // to client position.
     syncable::Id server_prev_id = entry.ComputePrevIdFromServerPosition(
         entry.Get(syncable::SERVER_PARENT_ID));
     bool needs_reinsertion = !parent_matches ||
-         server_prev_id != entry.Get(syncable::PREV_ID);
+         server_prev_id != entry.GetPredecessorId();
     DVLOG_IF(1, needs_reinsertion) << "Insertion needed, server prev id "
         << " is " << server_prev_id << ", local prev id is "
-        << entry.Get(syncable::PREV_ID);
+        << entry.GetPredecessorId();
     const sync_pb::EntitySpecifics& specifics =
         entry.Get(syncable::SPECIFICS);
     const sync_pb::EntitySpecifics& server_specifics =
         entry.Get(syncable::SERVER_SPECIFICS);
     const sync_pb::EntitySpecifics& base_server_specifics =
         entry.Get(syncable::BASE_SERVER_SPECIFICS);
     std::string decrypted_specifics, decrypted_server_specifics;
     bool specifics_match = false;
     bool server_encrypted_with_default_key = false;
     if (specifics.has_encrypted()) {
@@ skipping 124 matching lines @@
     // backwards through all continuous conflicting predecessors, building a
     // stack of items to resolve in predecessor->successor order, then process
     // each item individually.
     list<Id> predecessors;
     Id prev_id = id;
     do {
       predecessors.push_back(prev_id);
       Entry entry(trans, syncable::GET_BY_ID, prev_id);
       // Any entry in conflict must be valid.
       CHECK(entry.good());
-      Id new_prev_id = entry.Get(syncable::PREV_ID);
+      Id new_prev_id = entry.GetPredecessorId();
       if (new_prev_id == prev_id)
         break;
       prev_id = new_prev_id;
     } while (processed_items.count(prev_id) == 0 &&
              simple_conflict_ids.count(prev_id) > 0);  // Excludes root.
     while (!predecessors.empty()) {
       id = predecessors.back();
       predecessors.pop_back();
       ProcessSimpleConflict(trans, id, cryptographer, status);
       processed_items.insert(id);
     }
   }
   return;
 }
 
 }  // namespace syncer