fix warning

pkg/analyzer/test/generated/engine_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.engine_test;
 
 import 'dart:async';
@@ skipping 1673 matching lines @@
     Source libBSource = _addSource("/libB.dart", "library libB;");
     _analyzeAll_assertFinished();
     expect(
         _context.getResolvedHtmlUnit(htmlSource),
         isNotNull,
         reason: "htmlUnit resolved 1");
     expect(
         _context.getResolvedCompilationUnit2(libBSource, libBSource),
         isNotNull,
         reason: "libB resolved 2");
-    AnalysisErrorInfo errors = _context.getErrors(htmlSource);
     // TODO (danrubel) commented out to fix red bots
+//    AnalysisErrorInfo errors = _context.getErrors(htmlSource);
 //    expect(
 //        !_hasAnalysisErrorWithErrorSeverity(errors),
 //        isTrue,
 //        reason: "htmlSource doesn't have errors");
   }
 
   void test_performAnalysisTask_importedLibraryDelete() {
     Source libASource =
         _addSource("/libA.dart", "library libA; import 'libB.dart';");
     Source libBSource = _addSource("/libB.dart", "library libB;");
@@ skipping 5380 matching lines @@
   bool contains(Source source) => source == libB;
 }
 
 
 class _UniversalCachePartitionTest_test_setMaxCacheSize implements
     CacheRetentionPolicy {
   @override
   RetentionPriority getAstPriority(Source source, SourceEntry sourceEntry) =>
       RetentionPriority.LOW;
 }