analyzer_exp fixes

pkg/analyzer_experimental/test/services/test_utils.dart

 // Copyright (c) 2013, 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_utils;
 
-import 'dart:collection';
-
 import 'package:unittest/unittest.dart';
 
 import 'package:analyzer_experimental/src/generated/engine.dart' show AnalysisContext, AnalysisContextImpl;
 import 'package:analyzer_experimental/src/generated/source.dart';
 import 'package:analyzer_experimental/src/generated/error.dart';
 import 'package:analyzer_experimental/src/generated/scanner.dart';
 import 'package:analyzer_experimental/src/generated/ast.dart';
 import 'package:analyzer_experimental/src/generated/parser.dart';
 
 
@@ skipping 187 matching lines @@
   var parser = new Parser(null, listener);
   var statement = parser.parseStatement(token);
   expect(statement, isNotNull);
 
   if (expectedErrorCodes != null) {
     listener.expectErrors(expectedErrorCodes);
   }
 
   return statement;
 }