Make server use the common protocol classes

pkg/analysis_server/test/integration/analysis/highlights_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.
 
 import 'package:analysis_server/protocol/protocol_generated.dart';
+import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../support/integration_tests.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(AnalysisHighlightsTest);
   });
 }
@@ skipping 120 matching lines @@
       check(HighlightRegionType.PARAMETER, ['parameter']);
       check(HighlightRegionType.SETTER_DECLARATION, ['setter']);
       check(HighlightRegionType.TOP_LEVEL_VARIABLE,
           ['override', 'topLevelVariable']);
       check(HighlightRegionType.TYPE_NAME_DYNAMIC, ['dynamic']);
       check(HighlightRegionType.TYPE_PARAMETER, ['TypeParameter']);
       expect(highlights, isEmpty);
     });
   }
 }