Make some parser test helper methods non-static.

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

Index: pkg/analyzer/test/src/dart/analysis/defined_names_test.dart
diff --git a/pkg/analyzer/test/src/dart/analysis/defined_names_test.dart b/pkg/analyzer/test/src/dart/analysis/defined_names_test.dart
index bc34e50dc2621c6d9e58b582dc917ae9a638d97c..6b5131cb87cc593fe65d933fa90b94cd7e7cf7df 100644
--- a/pkg/analyzer/test/src/dart/analysis/defined_names_test.dart
+++ b/pkg/analyzer/test/src/dart/analysis/defined_names_test.dart
@@ -16,7 +16,7 @@ main() {
 }
 
 @reflectiveTest
-class DefinedNamesTest {
+class DefinedNamesTest extends ParserTestCase {
   test_classMemberNames() {
     DefinedNames names = _computeDefinedNames('''
 class A {
@@ -52,7 +52,7 @@ var G, H;
   }
 
   DefinedNames _computeDefinedNames(String code) {
-    CompilationUnit unit = ParserTestCase.parseCompilationUnit2(code);
+    CompilationUnit unit = parseCompilationUnit2(code);
     return computeDefinedNames(unit);
   }
 }