[Sync] Don't commit items with predecessors/parents in conflict.

chrome/browser/sync/sessions/ordered_commit_set.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROME_BROWSER_SYNC_SESSIONS_ORDERED_COMMIT_SET_H_
 #define CHROME_BROWSER_SYNC_SESSIONS_ORDERED_COMMIT_SET_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 22 matching lines @@
   explicit OrderedCommitSet(const browser_sync::ModelSafeRoutingInfo& routes);
   ~OrderedCommitSet();
 
   bool HaveCommitItem(const int64 metahandle) const {
     return inserted_metahandles_.count(metahandle) > 0;
   }
 
   void AddCommitItem(const int64 metahandle, const syncable::Id& commit_id,
                      syncable::ModelType type);
 
+  void Clear();
+
   const std::vector<syncable::Id>& GetAllCommitIds() const {
     return commit_ids_;
   }
 
   // Return the Id at index |position| in this OrderedCommitSet.  Note that
   // the index uniquely identifies the same logical item in each of:
   // 1) this OrderedCommitSet
   // 2) the CommitRequest sent to the server
   // 3) the list of EntryResponse objects in the CommitResponse.
   // These together allow re-association of the pre-commit Id with the
@@ skipping 56 matching lines @@
   std::vector<syncable::ModelType> types_;
 
   browser_sync::ModelSafeRoutingInfo routes_;
 };
 
 }  // namespace sessions
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_SESSIONS_ORDERED_COMMIT_SET_H_