HBASE-8954 TestSplitLogWorker#testPreemptTask failed

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1505889 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9017 Consolidate ChaosMonkey's random objects

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1505890 13f79535-47bb-0310-9956-ffa450edef68