Fix hang when opening sockets on ports that are not available.

tests/standalone/src/TimeoutTest.dart

Index: tests/standalone/src/TimeoutTest.dart
diff --git a/tests/standalone/src/TimeoutTest.dart b/tests/standalone/src/TimeoutTest.dart
index 8248721ce3324bfc990f997c4e4d0f7ddb0091bd..b14f4de3bdba867d7befa23a211046cd579e723f 100644
--- a/tests/standalone/src/TimeoutTest.dart
+++ b/tests/standalone/src/TimeoutTest.dart
@@ -6,6 +6,7 @@
 // A test that runs forever.
 void main() {
   final HOST = "127.0.0.1";
-  ServerSocket listenForever = new ServerSocket(HOST, 8001, 10);
+  // Use port 0 to chose free port.
+  ServerSocket listenForever = new ServerSocket(HOST, 0, 10);
   // Does not call listenForever.close();
 }