dart2js: fetch http Resources

tests/compiler/dart2js/mock_libraries.dart

 // Copyright (c) 2014, 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 for creating mock versions of platform and internal libraries.
 
 library mock_libraries;
 
 String buildLibrarySource(
     Map<String, String> elementMap,
@@ skipping 63 matching lines @@
   'print': 'print(var obj) {}',
   'proxy': 'const proxy = 0;',
   'Object': r'''
       class Object {
         const Object();
         operator ==(other) { return true; }
         get hashCode => throw "Object.hashCode not implemented.";
         String toString() { return null; }
         noSuchMethod(im) { throw im; }
       }''',
+  'Resource': 'class Resource {}',
   'StackTrace': 'abstract class StackTrace {}',
   'String': 'class String implements Pattern {}',
   'Symbol': 'class Symbol { final name; const Symbol(this.name); }',
   'Type': 'class Type {}',
   'Pattern': 'abstract class Pattern {}',
 };
 
 const String DEFAULT_PATCH_CORE_SOURCE = r'''
 import 'dart:_js_helper';
 import 'dart:_interceptors';
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 const Map<String, String> ASYNC_AWAIT_LIBRARY = const <String, String>{
   '_wrapJsFunctionForAsync': '_wrapJsFunctionForAsync(f) {}',
   '_asyncHelper': '_asyncHelper(o, f, c) {}',
 };
 
 const Map<String, String> DEFAULT_MIRRORS_LIBRARY = const <String, String>{
   'Comment': 'class Comment {}',
   'MirrorSystem': 'class MirrorSystem {}',
   'MirrorsUsed': 'class MirrorsUsed {}',
 };