only suggest types when completing from a library prefix in parameter list

pkg/analysis_server/lib/src/services/completion/combinator_computer.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 services.completion.computer.dart.combinator;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart'
     hide Element, ElementKind;
@@ skipping 53 matching lines @@
 
 /**
  * A `_CombinatorSuggestionBuilder` determines which imported classes
  * and top level variables should be suggested and builds those suggestions.
  * This operation is instantiated during `computeFast`
  * and calculates the suggestions during `computeFull`.
  */
 class _CombinatorSuggestionBuilder extends LibraryElementSuggestionBuilder {
   _CombinatorSuggestionBuilder(
       DartCompletionRequest request, CompletionSuggestionKind kind)
-      : super(request, kind);
+      : super(request, kind, false);
 
   Future<bool> execute(AstNode node) {
     var directive = node.getAncestor((parent) => parent is NamespaceDirective);
     if (directive is NamespaceDirective) {
       LibraryElement library = directive.uriElement;
       if (library != null) {
         library.visitChildren(this);
       }
     }
     return new Future.value(false);
   }
 }