Added the ability for testrunner to start the HTTP server with a random port and communicate that p…

utils/testrunner/http_server.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 library http_server;
 import 'dart:io';
 import 'package:args/args.dart';
 
 /** An options parser for the server. */
 ArgParser getOptionParser() {
@@ skipping 33 matching lines @@
       'csv'  : 'text/csv',
       'htm'  : 'text/html',
       'html' : 'text/html',
       'txt'  : 'text/plain',
       'rtf'  : 'text/rtf',
       'mp4'  : 'video/mp4',
       'qt'   : 'video/quicktime',
       'vc1'  : 'video/vc1'
   };
 
-  HttpTestServer(port, this.staticFileDirectory) {
+  HttpTestServer(int port, this.staticFileDirectory) {
     server = new HttpServer();
-    server.listen("127.0.0.1", port);
+    try {
+      server.listen("127.0.0.1", port);
+      print('Server listening on port $port');
+    } catch (e) {
+      print('Server listen on port $port failed');
+      throw e;
+    }
     server.onError = (e) {
     };
     server.defaultRequestHandler =
       (HttpRequest request, HttpResponse response) {
         try {
           if (staticFileDirectory != null) {
             String fname = request.path;
             String path = '$staticFileDirectory$fname';
             File f = new File(path);
             if (f.existsSync()) {
@@ skipping 26 matching lines @@
       server.addRequestHandler(matcher, handler);
     } else {
       server.addRequestHandler(matcher, handler.onRequest);
     }
   }
 
   void close() {
     server.close();
   }
 }