$ grep DVLOG v4_*

This should only lead to cases when something unexpected happens.

Current candidates for removal:
v4_local_database_manager.cc:  DVLOG(1) << "V4LocalDatabaseManager::V4LocalDatabaseManager: "
v4_store.cc:  DVLOG(1) << "Update successful: " << *this;
v4_store.cc:  DVLOG(1) << "ApplyUpdate: response_size: " << response->ByteSize() << " : "