Make server use the common protocol classes

pkg/analysis_server/test/integration/analysis/package_root_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:path/path.dart' as path;
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../support/integration_tests.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(SetAnalysisRootsTest);
   });
@@ skipping 53 matching lines @@
               navigationTargets[navigationTargetIndex];
           String navigationFile =
               navigationTargetFiles[navigationTarget.fileIndex];
           expect(navigationFile, equals(normalizedFooBarPath));
         }
       }
       expect(found, isTrue);
     });
   }
 }