Report HintCode.UNUSED_LOCAL_VARIABLE for local variables whose value is never used.

pkg/analysis_server/test/services/correction/fix_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.
 
 library test.services.correction.fix;
 
 import 'package:analysis_server/src/protocol.dart' hide AnalysisError;
 import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/index/local_memory_index.dart';
@@ skipping 2286 matching lines @@
       'my_pkg': [myPkgFolder]
     });
     context.sourceFactory = new SourceFactory(
         [AbstractContextTest.SDK_RESOLVER, resourceResolver, pkgResolver]);
     // force 'my_pkg' resolution
     addSource('/tmp/other.dart', "import 'package:my_pkg/my_lib.dart';");
   }
 
   AnalysisError _findErrorToFix() {
     List<AnalysisError> errors = context.computeErrors(testSource);
+    errors.removeWhere((error) {
+      return error.errorCode == HintCode.UNUSED_LOCAL_VARIABLE;
+    });
     if (checkHasSingleError) {
       expect(errors, hasLength(1));
     }
     return errors[0];
   }
 
   List<Position> _findResultPositions(List<String> searchStrings) {
     List<Position> positions = <Position>[];
     for (String search in searchStrings) {
       int offset = resultCode.indexOf(search);
       int length = getLeadingIdentifierLength(search);
       positions.add(new Position(testFile, offset));
     }
     return positions;
   }
 
   void _indexTestUnit(String code) {
     resolveTestUnit(code);
     index.indexUnit(context, testUnit);
   }
 }