Review feedback.

Author: Marcelo Vanzin

yarn/common/src/main/scala/org/apache/spark/deploy/yarn/ApplicationMaster.scala

@@ -190,7 +190,8 @@ private[spark] class ApplicationMaster(args: ApplicationMasterArguments,
       conf = sparkConf, securityManager = securityMgr)._1
     actor = waitForSparkDriver()
     addAmIpFilter()
-    registerAM(sparkConf.get("spark.driver.appUIAddress", ""), "")
+    registerAM(sparkConf.get("spark.driver.appUIAddress", ""),
+      sparkConf.get("spark.driver.appUIHistoryAddress", ""))
 
     // In client mode the actor will stop the reporter thread.
     reporterThread.join()

yarn/common/src/main/scala/org/apache/spark/deploy/yarn/YarnRMClient.scala

@@ -50,8 +50,8 @@ trait YarnRMClient {
   /**
    * Shuts down the AM. Guaranteed to only be called once.
    *
-   * @param registered Whether the AM was successfully registered with the RM.
    * @param status The final status of the AM.
+   * @param diagnostics Diagnostics message to include in the final status.
    */
   def shutdown(status: FinalApplicationStatus, diagnostics: String = ""): Unit
 

yarn/common/src/main/scala/org/apache/spark/deploy/yarn/YarnSparkHadoopUtil.scala

@@ -193,14 +193,14 @@ object YarnSparkHadoopUtil {
     }
   }
 
-  def lookupRack(conf: Configuration, host: String): String = {
+  private[spark] def lookupRack(conf: Configuration, host: String): String = {
     if (!hostToRack.contains(host)) {
       populateRackInfo(conf, host)
     }
     hostToRack.get(host)
   }
 
-  def populateRackInfo(conf: Configuration, hostname: String) {
+  private[spark] def populateRackInfo(conf: Configuration, hostname: String) {
     Utils.checkHost(hostname)
 
     if (!hostToRack.containsKey(hostname)) {

yarn/common/src/main/scala/org/apache/spark/scheduler/cluster/YarnClientSchedulerBackend.scala

@@ -19,7 +19,7 @@ package org.apache.spark.scheduler.cluster
 
 import org.apache.hadoop.yarn.api.records.{ApplicationId, YarnApplicationState}
 import org.apache.spark.{SparkException, Logging, SparkContext}
-import org.apache.spark.deploy.yarn.{ApplicationMaster, Client, ClientArguments, YarnSparkHadoopUtil}
+import org.apache.spark.deploy.yarn.{Client, ClientArguments, YarnSparkHadoopUtil}
 import org.apache.spark.scheduler.TaskSchedulerImpl
 
 import scala.collection.mutable.ArrayBuffer