Remove the Path class from dart:io

sdk/lib/io/http_impl.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.
 
 part of dart.io;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
   final Completer _dataCompleter = new Completer();
   Stream<List<int>> _stream;
@@ skipping 1572 matching lines @@
     var port;
     var path;
     if (uri.host.isEmpty) {
       host = previous.uri.host;
       port = previous.uri.port;
     }
     if (uri.scheme.isEmpty) {
       scheme = previous.uri.scheme;
     }
     if (!uri.path.startsWith('/')) {
-      var absolute = new Path.raw(previous.uri.path).directoryPath;
-      absolute = absolute.join(new Path.raw(u.path));
+      var absolute = new _Path.raw(previous.uri.path).directoryPath;
+      absolute = absolute.join(new _Path.raw(u.path));
       path = absolute.canonicalize().toString();
     }
     replaceComponents(scheme: scheme, host: host, port: port, path: path);
     return openUrl(method, uri).then((_HttpClientRequest request) {
           // Only follow redirects if initial request did.
           request.followRedirects = previous.followRedirects;
           // Allow same number of redirects.
           request.maxRedirects = previous.maxRedirects;
           // Copy headers.
           for (var header in previous.headers._headers.keys) {
@@ skipping 840 matching lines @@
   final Uri location;
 }
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }