Add Windows support.

lib/src/runner/browser/server.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.browser.server;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 313 matching lines @@
   Future _compileSuite(String dartPath) {
     return _compileFutures.putIfAbsent(dartPath, () {
       var dir = new Directory(_compiledDir).createTempSync('test_').path;
       var jsPath = p.join(dir, p.basename(dartPath) + ".js");
 
       return _compilers.compile(dartPath, jsPath, packageRoot: _packageRoot)
           .then((_) {
         if (_closed) return;
 
         _jsHandler.add(
-            p.relative(dartPath, from: _root) + '.browser_test.dart.js',
+            p.toUri(p.relative(dartPath, from: _root)).path +
+                '.browser_test.dart.js',
             (request) {
           return new shelf.Response.ok(new File(jsPath).readAsStringSync(),
               headers: {'Content-Type': 'application/javascript'});
         });
       });
     });
   }
 
   /// Returns the [BrowserManager] for [platform], which should be a browser.
   ///
@@ skipping 69 matching lines @@
       if (_pubServeUrl == null) {
         new Directory(_compiledDir).deleteSync(recursive: true);
       } else {
         _http.close();
       }
 
       _closeCompleter.complete();
     }).catchError(_closeCompleter.completeError);
   }
 }