Remove JavaStringBuilder

pkg/analyzer/test/generated/parser_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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.parser_test;
 
 import 'package:analyzer/src/generated/java_core.dart';
@@ skipping 30 matching lines @@
    * A list containing the errors found while traversing the AST structure.
    */
   List<String> _errors = new List<String>();
 
   /**
    * Assert that no errors were found while traversing any of the AST structures that have been
    * visited.
    */
   void assertValid() {
     if (!_errors.isEmpty) {
-      JavaStringBuilder builder = new JavaStringBuilder();
-      builder.append("Invalid AST structure:");
+      StringBuffer buffer = new StringBuffer();
+      buffer.write("Invalid AST structure:");
       for (String message in _errors) {
-        builder.append("\r\n   ");
-        builder.append(message);
+        buffer.write("\r\n   ");
+        buffer.write(message);
       }
-      JUnitTestCase.fail(builder.toString());
+      JUnitTestCase.fail(buffer.toString());
     }
   }
 
   @override
   Object visitNode(AstNode node) {
     _validate(node);
     return super.visitNode(node);
   }
 
   /**
@@ skipping 8192 matching lines @@
 main() {
   _ut.groupSep = ' | ';
   runReflectiveTests(ComplexParserTest);
   runReflectiveTests(ErrorParserTest);
   runReflectiveTests(IncrementalParserTest);
   runReflectiveTests(NonErrorParserTest);
   runReflectiveTests(RecoveryParserTest);
   runReflectiveTests(ResolutionCopierTest);
   runReflectiveTests(SimpleParserTest);
 }