Make Analysis Server tests use MockSdk again.

pkg/analysis_server/test/services/dependencies/reachable_source_collector_test.dart

 // Copyright (c) 2015, 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.services.dependencies.import_collector;
 
 import 'package:analysis_server/src/services/dependencies/reachable_source_collector.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ skipping 26 matching lines @@
     Source lib1 = addSource(
         '/lib1.dart',
         '''
 import "lib2.dart";
 import "dart:html";''');
     Source lib2 = addSource('/lib2.dart', 'import "lib1.dart";');
 
     Source lib3 = addSource('/lib3.dart', 'import "lib4.dart";');
     addSource('/lib4.dart', 'import "lib3.dart";');
 
-    {
-      Map<String, List<String>> imports = importsFor(lib1);
-      expect(imports.keys, contains('file:///lib1.dart'));
-      expect(imports.keys, contains('file:///lib2.dart'));
-      expect(imports.keys, contains('dart:core'));
-      expect(imports.keys, contains('dart:html'));
-      expect(imports.keys, contains('dart:math'));
-      expect(imports.keys, isNot(contains('file:///lib3.dart')));
-      expect(imports['file:///lib1.dart'],
-          unorderedEquals(['dart:core', 'dart:html', 'file:///lib2.dart']));
-    }
+    Map<String, List<String>> imports = importsFor(lib1);
+
+    // Verify keys.
+    expect(
+        imports.keys,
+        unorderedEquals([
+          'dart:_internal',
+          'dart:async',
+          'dart:core',
+          'dart:html',
+          'dart:math',
+          'file:///lib1.dart',
+          'file:///lib2.dart',
+        ]));
+    // Values.
+    expect(imports['file:///lib1.dart'],
+        unorderedEquals(['dart:core', 'dart:html', 'file:///lib2.dart']));
 
     // Check transitivity.
     expect(importsFor(lib2).keys, contains('dart:html'));
 
     // Cycles should be OK.
-    {
-      Map<String, List<String>> imports = importsFor(lib3);
-      expect(imports.keys, contains('file:///lib3.dart'));
-      expect(imports.keys, contains('file:///lib4.dart'));
-      expect(imports.keys, contains('dart:core'));
-      expect(imports.keys, contains('dart:math'));
-    }
+    expect(
+        importsFor(lib3).keys,
+        unorderedEquals([
+          'dart:_internal',
+          'dart:async',
+          'dart:core',
+          'dart:math',
+          'file:///lib3.dart',
+          'file:///lib4.dart'
+        ]));
   }
 }