sync: Start moving away from PREV_ID and NEXT_ID

sync/internal_api/write_node.cc

Index: sync/internal_api/write_node.cc
diff --git a/sync/internal_api/write_node.cc b/sync/internal_api/write_node.cc
index 0c1c2ad469963c27ee4d936eda1f275e8d85f5c8..2057c25f9b10f9e0cd9613a39251a8bbfde106dc 100644
--- a/sync/internal_api/write_node.cc
+++ b/sync/internal_api/write_node.cc
@@ -461,7 +461,7 @@ bool WriteNode::SetPosition(const BaseNode& new_parent,
 
   // Filter out redundant changes if both the parent and the predecessor match.
   if (new_parent_id == entry_->Get(syncable::PARENT_ID)) {
-    const syncable::Id& old = entry_->Get(syncable::PREV_ID);
+    const syncable::Id& old = entry_->GetPredecessorId();
     if ((!predecessor && old.IsRoot()) ||
         (predecessor && (old == predecessor->GetEntry()->Get(syncable::ID)))) {
       return true;