Move file_system libraries into 'analyzer'.

pkg/analysis_server/test/domain_search_test.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 test.domain.search;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_search.dart';
 import 'package:analysis_server/src/protocol.dart';
-import 'package:analysis_server/src/resource.dart';
+import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:unittest/unittest.dart';
 
 import 'analysis_abstract.dart';
 import 'mocks.dart';
 import 'reflective_tests.dart';
 import 'package:analyzer/src/index/local_index.dart';
 import 'package:analyzer/index/index.dart';
 
 main() {
   groupSep = ' | ';
@@ skipping 87 matching lines @@
           if (location.element.name == 'AAA') {
             hasClassAAA = true;
           }
         }
         expect(hasClassFunction, isTrue, reason: locations.toString());
         expect(hasClassAAA, isTrue, reason: locations.toString());
       });
     });
   }
 }