revert attributes change

Author: ericl

mllib/src/main/scala/org/apache/spark/ml/attribute/attributes.scala

@@ -124,28 +124,18 @@ private[attribute] trait AttributeFactory {
   private[attribute] def fromMetadata(metadata: Metadata): Attribute
 
   /**
-   * Creates an [[Attribute]] from a [[StructField]] instance, optionally preserving name.
+   * Creates an [[Attribute]] from a [[StructField]] instance.
    */
-  private[ml] def decodeStructField(field: StructField, preserveName: Boolean): Attribute = {
+  def fromStructField(field: StructField): Attribute = {
     require(field.dataType.isInstanceOf[NumericType])
     val metadata = field.metadata
     val mlAttr = AttributeKeys.ML_ATTR
     if (metadata.contains(mlAttr)) {
-      val attr = fromMetadata(metadata.getMetadata(mlAttr))
-      if (preserveName) {
-        attr
-      } else {
-        attr.withName(field.name)
-      }
+      fromMetadata(metadata.getMetadata(mlAttr)).withName(field.name)
     } else {
       UnresolvedAttribute
     }
   }
-
-  /**
-   * Creates an [[Attribute]] from a [[StructField]] instance.
-   */
-  def fromStructField(field: StructField): Attribute = decodeStructField(field, false)
 }
 
 /**