Extract testing utilities into a separate package.

pkg/analysis_server/test/package_uri_resolver_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.resolver.package;
 
 import 'dart:collection';
 
 import 'package:analysis_server/src/package_uri_resolver.dart';
+import 'package:analysis_testing/reflective_tests.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:unittest/unittest.dart';
 
-import 'reflective_tests.dart';
 
 main() {
   groupSep = ' | ';
 
   group('PackageMapUriResolver', () {
     runReflectiveTests(_PackageMapUriResolverTest);
   });
 }
 
 
@@ skipping 127 matching lines @@
 
   void test_resolve_package_notInMap() {
     UriResolver resolver = new PackageMapUriResolver(provider, EMPTY_MAP);
     Uri uri = Uri.parse('package:analyzer/analyzer.dart');
     Source result = resolver.resolveAbsolute(uri);
     expect(result, isNotNull);
     expect(result.exists(), isFalse);
     expect(result.fullName, 'package:analyzer/analyzer.dart');
   }
 }