SPARK-1801. expose InterruptibleIterator and TaskKilledException in developer api

Author: koertkuipers

core/src/main/scala/org/apache/spark/InterruptibleIterator.scala

@@ -17,11 +17,14 @@
 
 package org.apache.spark
 
+import org.apache.spark.annotation.DeveloperApi
+
 /**
  * An iterator that wraps around an existing iterator to provide task killing functionality.
  * It works by checking the interrupted flag in [[TaskContext]].
  */
-private[spark] class InterruptibleIterator[+T](val context: TaskContext, val delegate: Iterator[T])
+@DeveloperApi
+class InterruptibleIterator[+T](val context: TaskContext, val delegate: Iterator[T])
   extends Iterator[T] {
 
   def hasNext: Boolean = {

core/src/main/scala/org/apache/spark/TaskKilledException.scala

@@ -17,7 +17,10 @@
 
 package org.apache.spark
 
+import org.apache.spark.annotation.DeveloperApi
+
 /**
  * Exception for a task getting killed.
  */
-private[spark] class TaskKilledException extends RuntimeException
+@DeveloperApi
+class TaskKilledException extends RuntimeException