Fixed racey testShutdown test, where echoServer was throwing an exception after trying to write to …

tests/standalone/io/raw_synchronous_socket_test.dart

Index: tests/standalone/io/raw_synchronous_socket_test.dart
diff --git a/tests/standalone/io/raw_synchronous_socket_test.dart b/tests/standalone/io/raw_synchronous_socket_test.dart
index 3f3e95f53b97c3d80dc8c442fdd7f3e6314884e3..2b005c7a7070d1fcbfe58c32a0e0ac0424833b75 100644
--- a/tests/standalone/io/raw_synchronous_socket_test.dart
+++ b/tests/standalone/io/raw_synchronous_socket_test.dart
@@ -388,12 +388,11 @@ Future testShutdown() async {
         () => socket.readSync(data.length), (e) => e is SocketException);
     socket.closeSync();
 
-    // Close the socket for reading, do a write, and see if we can get any
-    // response from the server (we shouldn't be able to).
+    // Close the socket for reading then try and perform a read. This should
+    // cause a SocketException.
     socket = RawSynchronousSocket.connectSync(
         LOOPBACK_IP_V4_STRING, serverInternetPort);
     socket.shutdown(SocketDirection.RECEIVE);

[siva, 2017/04/27 18:28:56]

Instead of deleting the write which is a good test to see if we are still able
to write after doing a READ shutdown, why not send some data which the echo
server recognizes and does not echo it back.

-    socket.writeFromSync(data);
     // Throws exception when the socket is closed for RECEIVE.
     Expect.throws(
         () => socket.readSync(data.length), (e) => e is SocketException);