Make server use the common protocol classes

pkg/analysis_server/test/services/completion/dart/uri_contributor_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:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/services/completion/dart/uri_contributor.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
+import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:path/path.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'completion_contributor_util.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(UriContributorTest);
     defineReflectiveTests(UriContributorWindowsTest);
@@ skipping 604 matching lines @@
     assertNotSuggested('foo/');
     assertNotSuggested('foo/bar.dart');
     assertSuggest('../blat.dart', csKind: CompletionSuggestionKind.IMPORT);
   }
 }
 
 class _TestWinResourceProvider extends MemoryResourceProvider {
   @override
   Context get pathContext => windows;
 }