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

tests/standalone/io/http_content_length_test.dart

Index: tests/standalone/io/http_content_length_test.dart
diff --git a/tests/standalone/io/http_content_length_test.dart b/tests/standalone/io/http_content_length_test.dart
index 5a082f2a9f191abcac70c2f30c4f57ac230c9568..28f9ecda4e1f65cd1d353cbe719d3aec6f78e9f5 100644
--- a/tests/standalone/io/http_content_length_test.dart
+++ b/tests/standalone/io/http_content_length_test.dart
@@ -3,8 +3,8 @@
 // BSD-style license that can be found in the LICENSE file.
 //
 
-#import("dart:isolate");
-#import("dart:io");
+import "dart:isolate";
+import "dart:io";
 
 void testNoBody(int totalConnections, bool explicitContentLength) {
   HttpServer server = new HttpServer();