Convert //sync from scoped_ptr to std::unique_ptr

sync/internal_api/public/simple_metadata_change_list.h

 // Copyright 2015 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 SYNC_INTERNAL_API_PUBLIC_SIMPLE_METADATA_CHANGE_LIST_H_
 #define SYNC_INTERNAL_API_PUBLIC_SIMPLE_METADATA_CHANGE_LIST_H_
 
 #include <map>
 #include <string>
 
@@ skipping 40 matching lines @@
   const DataTypeStateChange& GetDataTypeStateChange() const;
 
   // Moves all currently accumulated changes into the write batch, clear out
   // local copies. Calling this multiple times will work, but should not be
   // necessary.
   void TransferChanges(ModelTypeStore* store,
                        ModelTypeStore::WriteBatch* write_batch);
 
  private:
   MetadataChanges metadata_changes_;
-  scoped_ptr<DataTypeStateChange> state_change_;
+  std::unique_ptr<DataTypeStateChange> state_change_;
 };
 
 }  // namespace syncer_v2
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_SIMPLE_METADATA_CHANGE_LIST_H_