Make some parser test helper methods non-static.

pkg/analyzer/test/src/dart/analysis/referenced_names_test.dart

 // Copyright (c) 2016, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/analysis/referenced_names.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../../generated/parser_test.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(ReferencedNamesBuilderTest);
   });
 }
 
 @reflectiveTest
-class ReferencedNamesBuilderTest {
+class ReferencedNamesBuilderTest extends ParserTestCase {
   test_class_constructor() {
     Set<String> names = _computeReferencedNames('''
 class U {
   U.named(A a, B b) {
     C c = null;
   }
 }
 ''');
     expect(names, unorderedEquals(['A', 'B', 'C']));
   }
@@ skipping 346 matching lines @@
   L5;
   L6;
   L7;
   L8;
 }
 ''');
     expect(names, unorderedEquals(['A', 'B', 'C']));
   }
 
   Set<String> _computeReferencedNames(String code) {
-    CompilationUnit unit = ParserTestCase.parseCompilationUnit2(code);
+    CompilationUnit unit = parseCompilationUnit2(code);
     return computeReferencedNames(unit);
   }
 }