Remove an obsolete error from the spec and an obsolete command-line flag

pkg/analysis_server/lib/src/search/search_domain.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 search.domain;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
@@ skipping 162 matching lines @@
         new TypeHierarchyComputer(searchEngine, element);
     List<protocol.TypeHierarchyItem> items = await computer.compute();
     protocol.Response response =
         new protocol.SearchGetTypeHierarchyResult(hierarchyItems: items)
             .toResponse(request.id);
     server.sendResponse(response);
   }
 
   @override
   protocol.Response handleRequest(protocol.Request request) {
-    if (searchEngine == null) {
-      return new protocol.Response.noIndexGenerated(request);
-    }
     try {
       String requestName = request.method;
       if (requestName == SEARCH_FIND_ELEMENT_REFERENCES) {
         findElementReferences(request);
         return protocol.Response.DELAYED_RESPONSE;
       } else if (requestName == SEARCH_FIND_MEMBER_DECLARATIONS) {
         findMemberDeclarations(request);
         return protocol.Response.DELAYED_RESPONSE;
       } else if (requestName == SEARCH_FIND_MEMBER_REFERENCES) {
         findMemberReferences(request);
@@ skipping 29 matching lines @@
   void _sendTypeHierarchyNull(protocol.Request request) {
     protocol.Response response =
         new protocol.SearchGetTypeHierarchyResult().toResponse(request.id);
     server.sendResponse(response);
   }
 
   static protocol.SearchResult toResult(SearchMatch match) {
     return protocol.newSearchResult_fromMatch(match);
   }
 }