Use utf-8 encoding for listing and error page, in http_server VirtualDirectory.

pkg/http_server/test/virtual_directory_test.dart

 // Copyright (c) 2013, 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.
 
 import 'dart:async';
 import 'dart:io';
 
 import "package:http_server/http_server.dart";
 import 'package:path/path.dart' as pathos;
 import "package:unittest/unittest.dart";
@@ skipping 122 matching lines @@
         var virDir = new VirtualDirectory(dir.path);
         new Directory('${dir.path}/alert(\'hacked!\');').createSync();
         virDir.allowDirectoryListing = true;
 
         return getAsString(virDir, '/alert(\'hacked!\');')
           .then((result) {
             expect(result, contains('/alert('hacked!');/'));
           });
       });
 
+      testVirtualDir('non-ascii-dir', (dir) {
+        var virDir = new VirtualDirectory(dir.path);
+        new Directory('${dir.path}/æøå').createSync();
+        virDir.allowDirectoryListing = true;
+
+        return getAsString(virDir, '/')
+          .then((result) {
+            expect(result, contains('æøå'));
+          });
+      });
+
+      testVirtualDir('content-type', (dir) {
+        var virDir = new VirtualDirectory(dir.path);
+        virDir.allowDirectoryListing = true;
+
+        return getHeaders(virDir, '/')
+          .then((headers) {
+            var contentType = headers.contentType.toString();
+            expect(contentType, 'text/html; charset=utf-8');
+          });
+      });
+
       if (!Platform.isWindows) {
         testVirtualDir('recursive-link', (dir) {
           var link = new Link('${dir.path}/recursive')..createSync('.');
           var virDir = new VirtualDirectory(dir.path);
           virDir.allowDirectoryListing = true;
 
           return Future.wait([
               getAsString(virDir, '/').then(
                   (s) => s.contains('recursive/')),
               getAsString(virDir, '/').then(
@@ skipping 412 matching lines @@
           return virDir.serveFile(new File('${d.path}/file'), request);
         };
 
         return getAsString(virDir, '/')
           .then((result) {
             expect(result, 'file contents');
           });
     });
   });
 }