Clean up imports / comments (minor)

Author: andrewor14

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

@@ -305,9 +305,8 @@ private[spark] object SparkConf {
   /**
    * Return whether the given config should be passed to an executor on start-up.
    *
-   * When connecting to the scheduler, the executor backend needs certain akka and authentication
-   * settings to connect to the scheduler, while the rest of the spark configs can be inherited
-   * from the driver later.
+   * Certain akka and authentication configs are required of the executor when it connects to
+   * the scheduler, while the rest of the spark configs can be inherited from the driver later.
    */
   def isExecutorStartupConf(name: String): Boolean = {
     isAkkaConf(name) || name.startsWith("spark.akka") || name.startsWith("spark.auth")

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

@@ -37,9 +37,7 @@ import org.apache.hadoop.yarn.api.protocolrecords._
 import org.apache.hadoop.yarn.api.records._
 import org.apache.hadoop.yarn.conf.YarnConfiguration
 import org.apache.hadoop.yarn.util.Records
-
 import org.apache.spark.{SparkException, Logging, SparkConf, SparkContext}
-import org.apache.spark.util.Utils
 
 /**
  * The entry point (starting in Client#main() and Client#run()) for launching Spark on YARN. The
@@ -386,7 +384,6 @@ trait ClientBase extends Logging {
     // Forward the Spark configuration to the application master / executors.
     // TODO: it might be nicer to pass these as an internal environment variable rather than
     // as Java options, due to complications with string parsing of nested quotes.
-    // TODO: Use Utils.sparkJavaOpts here once we figure out how to deal with quotes and backslashes
     for ((k, v) <- sparkConf.getAll) {
       javaOpts += "-D" + k + "=" + "\\\"" + v + "\\\""
     }

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

@@ -31,7 +31,6 @@ import org.apache.hadoop.yarn.conf.YarnConfiguration
 import org.apache.hadoop.yarn.util.{ConverterUtils, Records}
 
 import org.apache.spark.{Logging, SparkConf}
-import org.apache.spark.util.Utils
 
 trait ExecutorRunnableUtil extends Logging {
 
@@ -67,7 +66,6 @@ trait ExecutorRunnableUtil extends Logging {
     // registers with the Scheduler and transfers the spark configs. Since the Executor backend
     // uses Akka to connect to the scheduler, the akka settings are needed as well as the
     // authentication settings.
-    // TODO: Use Utils.sparkJavaOpts here once we figure out how to deal with quotes and backslashes
     sparkConf.getAll.
       filter { case (k, v) => k.startsWith("spark.auth") || k.startsWith("spark.akka") }.
       foreach { case (k, v) => javaOpts += "-D" + k + "=" + "\\\"" + v + "\\\"" }