Sync: fixed Implicit Permanent Folders issues found when testing with alpha server

sync/engine/get_commit_ids.cc

 // Copyright 2013 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/get_commit_ids.h"
 
 #include <set>
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 435 matching lines @@
 
 bool Traversal::IsFull() const {
   return out_->size() >= max_entries_;
 }
 
 bool Traversal::HaveItem(int64 handle) const {
   return added_handles_.find(handle) != added_handles_.end();
 }
 
 bool Traversal::SupportsHierarchy(const syncable::Entry& item) const {
-  return !item.GetParentId().IsNull();
+  // Types with explicit server supported hierarchy only.
+  return IsTypeWithServerGeneratedRoot(item.GetModelType());
 }
 
 void Traversal::AppendManyToTraversal(
     const syncable::Directory::Metahandles& handles) {
   out_->insert(out_->end(), handles.begin(), handles.end());
   added_handles_.insert(handles.begin(), handles.end());
 }
 
 void Traversal::AppendToTraversal(int64 metahandle) {
   out_->push_back(metahandle);
@@ skipping 103 matching lines @@
   // Add moves and creates, and prepend their uncommitted parents.
   traversal.AddCreatesAndMoves(ready_unsynced_set);
 
   // Add all deletes.
   traversal.AddDeletes(ready_unsynced_set);
 }
 
 }  // namespace
 
 }  // namespace syncer