
The refState is a set of refs with SHA1s that fingerprints a document in the ChangeIndex. Before it was represented as a repeated byte[] field, which callers had to (de)serialize by calling RefState#{parseStates,toByteArray}. With this change, the (de)serialization is pushed out to the index implementations. Change-Id: Id49ccf3998b27d5c5f40124aaf1e3ad067a59b41