@Override
  public void onRegionSplitReverted(RegionInfo hri) throws IOException {
    if (initialized) {
      this.namespaceQuotaManager.removeRegionFromNamespaceUsage(hri);
    }
  }
Performs some action after {@link #update(GlobalQuotaSettingsImpl)} with the resulting quota
from the request action for the subject.
hbase-server/src/main/java/org/apache/hadoop/hbase/quotas/MasterQuotaManager.java