Index: wp-admin/includes/class-wp-filesystem-ssh2.php
===================================================================
--- wp-admin/includes/class-wp-filesystem-ssh2.php	(revision 18565)
+++ wp-admin/includes/class-wp-filesystem-ssh2.php	(working copy)
@@ -206,6 +206,13 @@
 		return $this->run_command(sprintf('chmod -R %o %s', $mode, escapeshellarg($file)), true);
 	}
 
+	/**
+	 * Change the ownership of a file / folder.
+	 * @param string $file Path to the file.
+	 * @param mixed $owner A user name or number.
+	 * @param bool $recursive (optional) If set True changes file owner recursivly. Defaults to False.
+	 * @return bool Returns true on success or false on failure.
+	 */
 	function chown($file, $owner, $recursive = false ) {
 		if ( ! $this->exists($file) )
 			return false;
Index: wp-admin/includes/class-wp-filesystem-ftpsockets.php
===================================================================
--- wp-admin/includes/class-wp-filesystem-ftpsockets.php	(revision 18565)
+++ wp-admin/includes/class-wp-filesystem-ftpsockets.php	(working copy)
@@ -174,10 +174,6 @@
 		return $this->ftp->chmod($file, $mode);
 	}
 
-	function chown($file, $owner, $recursive = false ) {
-		return false;
-	}
-
 	function owner($file) {
 		$dir = $this->dirlist($file);
 		return $dir[$file]['owner'];
Index: wp-admin/includes/class-wp-filesystem-ftpext.php
===================================================================
--- wp-admin/includes/class-wp-filesystem-ftpext.php	(revision 18565)
+++ wp-admin/includes/class-wp-filesystem-ftpext.php	(working copy)
@@ -168,9 +168,6 @@
 			return (bool)@ftp_site($this->link, sprintf('CHMOD %o %s', $mode, $file));
 		return (bool)@ftp_chmod($this->link, $mode, $file);
 	}
-	function chown($file, $owner, $recursive = false ) {
-		return false;
-	}
 	function owner($file) {
 		$dir = $this->dirlist($file);
 		return $dir[$file]['owner'];
Index: wp-admin/includes/class-wp-filesystem-base.php
===================================================================
--- wp-admin/includes/class-wp-filesystem-base.php	(revision 18565)
+++ wp-admin/includes/class-wp-filesystem-base.php	(working copy)
@@ -327,6 +327,18 @@
 	function is_binary( $text ) {
 		return (bool) preg_match('|[^\x20-\x7E]|', $text); //chr(32)..chr(127)
 	}
+
+	/**
+	 * Change the ownership of a file / folder.
+	 * Default behavior is to do nothing, override this in your subclass, if desired
+	 * @param string $file Path to the file.
+	 * @param mixed $owner A user name or number.
+	 * @param bool $recursive (optional) If set True changes file owner recursivly. Defaults to False.
+	 * @return bool Returns true on success or false on failure.
+	 */
+	function chown($file, $owner, $recursive = false ) {
+		return false;
+	}
 }
 
 ?>