Merge the dart:uri library into dart:core and update the Uri class

sdk/lib/_internal/compiler/implementation/util/uri_extras.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 uri_extras;
 
 import 'dart:math';
-import 'dart:uri';
 
 String relativize(Uri base, Uri uri, bool isWindows) {
   if (!base.path.startsWith('/')) {
     // Also throw an exception if [base] or base.path is null.
     throw new ArgumentError('Expected absolute path: ${base.path}');
   }
   if (!uri.path.startsWith('/')) {
     // Also throw an exception if [uri] or uri.path is null.
     throw new ArgumentError('Expected absolute path: ${uri.path}');
   }
   bool equalsNCS(String a, String b) {
     return a.toLowerCase() == b.toLowerCase();
   }
 
   String normalize(String path) {
     if (isWindows) {
       return path.toLowerCase();
     } else {
       return path;
     }
   }
 
   if (equalsNCS(base.scheme, 'file') &&
       equalsNCS(base.scheme, uri.scheme) &&
       base.userInfo == uri.userInfo &&
-      equalsNCS(base.domain, uri.domain) &&
+      equalsNCS(base.host, uri.host) &&
       base.port == uri.port &&
       uri.query == "" && uri.fragment == "") {
     if (normalize(uri.path).startsWith(normalize(base.path))) {
       return uri.path.substring(base.path.length);
     }
     List<String> uriParts = uri.path.split('/');
     List<String> baseParts = base.path.split('/');
     int common = 0;
     int length = min(uriParts.length, baseParts.length);
     while (common < length &&
@@ skipping 11 matching lines @@
       sb.write('../');
     }
     for (int i = common; i < uriParts.length - 1; i++) {
       sb.write('${uriParts[i]}/');
     }
     sb.write('${uriParts.last}');
     return sb.toString();
   }
   return uri.toString();
 }