HDFS-5276. FileSystem.Statistics should use thread-local counters to avoid multi-threaded performance issues on read/write.  (Colin Patrick McCabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1533668 13f79535-47bb-0310-9956-ffa450edef68
Merge remote-tracking branch: upstream/trunk