Remove BatchInfo.numRecords and a few renames

Author: zsxwing

streaming/src/main/scala/org/apache/spark/streaming/scheduler/BatchInfo.scala

@@ -58,11 +58,4 @@ case class BatchInfo(
    */
   def totalDelay: Option[Long] = schedulingDelay.zip(processingDelay)
     .map(x => x._1 + x._2).headOption
-
-  /**
-   * The number of recorders received by the receivers in this batch.
-   */
-  def numRecords: Long = receivedBlockInfo.map { case (_, infos) =>
-    infos.map(_.numRecords).sum
-  }.sum
 }

streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingJobProgressListener.scala

@@ -182,8 +182,8 @@ private[streaming] class StreamingJobProgressListener(ssc: StreamingContext)
    * Return all of the event rates for each receiver in each batch.
    */
   def receivedEventRateWithBatchTime: Map[Int, Seq[(Long, Double)]] = synchronized {
-    val latestBatches = retainedBatches.map { batchInfo =>
-      (batchInfo.batchTime.milliseconds, batchInfo.receiverNumRecords)
+    val latestBatches = retainedBatches.map { batchUIData =>
+      (batchUIData.batchTime.milliseconds, batchUIData.receiverNumRecords)
     }
     (0 until numReceivers).map { receiverId =>
       val eventRates = latestBatches.map {