Add more matchers for use in analysis server integration testing.

pkg/analysis_server/test/integration/analysis_domain_int_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.integration.analysis.domain;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_testing/reflective_tests.dart';
 import 'package:path/path.dart';
 import 'package:unittest/unittest.dart';
 
 import 'integration_tests.dart';
+import 'protocol_matchers.dart';
 
 @ReflectiveTestCase()
 class AnalysisDomainIntegrationTest extends
     AbstractAnalysisServerIntegrationTest {
   test_getHover() {
     String filename = 'test.dart';
     String pathname = normalizePath(filename);
     String text =
         r'''
 library lib.test;
@@ skipping 223 matching lines @@
       // Now there should be errors again, because the contents on disk are no
       // longer overridden.
       expect(currentAnalysisErrors[pathname], isNot(isEmpty));
     });
   }
 }
 
 main() {
   runReflectiveTests(AnalysisDomainIntegrationTest);
 }