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

tests/standalone/io/testing_server.dart

Index: tests/standalone/io/testing_server.dart
diff --git a/tests/standalone/io/testing_server.dart b/tests/standalone/io/testing_server.dart
index 59a0c9e6fd511ceac9801065666c4a5ac80748c2..e37a989d3f6bd27fd0efa12d8d1d534823ba8bb2 100644
--- a/tests/standalone/io/testing_server.dart
+++ b/tests/standalone/io/testing_server.dart
@@ -2,7 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-class TestingServer {
+part of ServerTest;
+
+abstract class TestingServer {
 
   static const HOST = "127.0.0.1";
   static const INIT = 0;
@@ -30,7 +32,7 @@ class TestingServer {
   ServerSocket _server;
 }
 
-class TestingServerTest {
+abstract class TestingServerTest {
 
   TestingServerTest.start(SendPort port)
       : _receivePort = new ReceivePort(),