Lint contribution refactoring.

pkg/analyzer/lib/src/generated/incremental_resolver.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 engine.incremental_resolver;
 
 import 'dart:collection';
 import 'dart:math' as math;
 
+import 'package:analyzer/src/services/lint.dart';
+
 import 'ast.dart';
 import 'element.dart';
 import 'engine.dart';
 import 'error.dart';
 import 'error_verifier.dart';
 import 'incremental_logger.dart' show logger, LoggingTimer;
 import 'java_engine.dart';
 import 'parser.dart';
 import 'resolver.dart';
 import 'scanner.dart';
@@ skipping 1861 matching lines @@
   String toString() => name;
 }
 
 
 class _TokenPair {
   final _TokenDifferenceKind kind;
   final Token oldToken;
   final Token newToken;
   _TokenPair(this.kind, this.oldToken, this.newToken);
 }