Update HoverInformation to include offset, length, kind.

pkg/analysis_server/lib/src/constants.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 constants;
 
 //
 // Server methods
 //
 const String SERVER_GET_VERSION = 'server.getVersion';
@@ skipping 69 matching lines @@
 const String ADDED = 'added';
 const String CHILDREN = 'children';
 const String CONTAINING_LIBRARY_NAME = 'containingLibraryName';
 const String CONTAINING_LIBRARY_PATH = 'containingLibraryPath';
 const String CONTENT = 'content';
 const String CORRECTION = 'correction';
 const String DART_DOC = 'dartdoc';
 const String DEFAULT = 'default';
 const String ELEMENT = 'element';
 const String ELEMENT_DESCRIPTION = 'elementDescription';
+const String ELEMENT_KIND = 'elementKind';
 const String EXCLUDED = 'excluded';
 const String ERROR_CODE = 'errorCode';
 const String ERRORS = 'errors';
 const String FILE = 'file';
 const String FILES = 'files';
 const String FIXES = 'fixes';
 const String FLAGS = 'flags';
 const String HOVERS = 'hovers';
 const String ID = 'id';
 const String INCLUDED = 'included';
@@ skipping 34 matching lines @@
 //
 // Analysis option names
 //
 const String ANALYZE_ANGULAR = 'analyzeAngular'; // boolean
 const String ANALYZE_POLYMER = 'analyzePolymer'; // boolean
 const String ENABLE_ASYNC = 'enableAsync'; // boolean
 const String ENABLE_DEFERRED_LOADING = 'enableDeferredLoading'; // boolean
 const String ENABLE_ENUMS = 'enableEnums'; // boolean
 const String GENERATE_DART2JS_HINTS = 'generateDart2jsHints'; // boolean
 const String GENERATE_HINTS = 'generateHints'; // boolean