Merge branch 'framed-thread-pool-utilization' of github.com:mhl-b/elasticsearch into framed-thread-pool-utilization

Author: mhl-b

server/src/main/java/org/elasticsearch/common/util/concurrent/TaskExecutionTimeTrackingEsThreadPoolExecutor.java

@@ -27,10 +27,8 @@
 import java.util.concurrent.RejectedExecutionHandler;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.LongAccumulator;
 import java.util.concurrent.atomic.LongAdder;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.Function;
 import java.util.function.Supplier;