Remove old #import, #source, and #library syntax from tests/standalone.

tests/standalone/io/directory_error_test.dart

Index: tests/standalone/io/directory_error_test.dart
diff --git a/tests/standalone/io/directory_error_test.dart b/tests/standalone/io/directory_error_test.dart
index fecb2231863f7d83feaafe508ccf1b46594b24ad..33799e4075cef6f3e8821fc942150b30864fff7d 100644
--- a/tests/standalone/io/directory_error_test.dart
+++ b/tests/standalone/io/directory_error_test.dart
@@ -4,8 +4,8 @@
 //
 // Dart test program for testing error handling in directory I/O.
 
-#import("dart:io");
-#import("dart:isolate");
+import "dart:io";
+import "dart:isolate";
 
 Directory tempDir() {
   return new Directory('').createTempSync();