@Override
  public void recordSyncOperationLatency(long latency) {
    syncOpLatency.add(latency);
  }
Class that transitions metrics from MetricsZooKeeper into the metrics subsystem. Implements
BaseSource through BaseSourceImpl, following the pattern.
hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/zookeeper/MetricsZooKeeperSourceImpl.java