Add Windows support.

lib/src/runner/loader.dart

 // Copyright (c) 2015, 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 test.runner.loader;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
 
@@ skipping 164 matching lines @@
       if (_pubServeUrl != null) {
         var url = _pubServeUrl.resolve(
             p.relative(path, from: 'test') + '.vm_test.dart');
         return Isolate.spawnUri(url, [], {
           'reply': receivePort.sendPort,
           'metadata': metadata.serialize()
         }).then((isolate) => new IsolateWrapper(isolate, () {}))
             .catchError((error, stackTrace) {
           if (error is! IsolateSpawnException) throw error;
 
-          if (error.message.contains("OS Error: Connection refused")) {
+          if (error.message.contains("OS Error: Connection refused") ||
+              error.message.contains("The remote computer refused")) {
             throw new LoadException(path,
                 "Error getting $url: Connection refused\n"
                 'Make sure "pub serve" is running.');
           } else if (error.message.contains("404 Not Found")) {
             throw new LoadException(path,
                 "Error getting $url: 404 Not Found\n"
                 'Make sure "pub serve" is serving the test/ directory.');
           }
 
           throw new LoadException(path, error);
         });
       } else {
         return runInIsolate('''
 import "package:test/src/backend/metadata.dart";
 import "package:test/src/runner/vm/isolate_listener.dart";
 
 import "${p.toUri(p.absolute(path))}" as test;
 
 void main(_, Map message) {
   var sendPort = message['reply'];
   var metadata = new Metadata.deserialize(message['metadata']);
   IsolateListener.start(sendPort, metadata, () => test.main);
 }
 ''', {
           'reply': receivePort.sendPort,
           'metadata': metadata.serialize()
-        }, packageRoot: _packageRoot);
+        }, packageRoot: p.toUri(_packageRoot));
       }
     }).catchError((error, stackTrace) {
       receivePort.close();
       if (error is LoadException) throw error;
       return new Future.error(new LoadException(path, error), stackTrace);
     }).then((isolate) {
       _isolates.add(isolate);
       return receivePort.first;
     }).then((response) {
       if (response["type"] == "loadException") {
@@ skipping 16 matching lines @@
   Future close() {
     for (var isolate in _isolates) {
       isolate.kill();
     }
     _isolates.clear();
 
     if (_browserServerCompleter == null) return new Future.value();
     return _browserServer.then((browserServer) => browserServer.close());
   }
 }