exclude suggestions from other contexts

pkg/analysis_server/lib/src/services/completion/dart_completion_cache.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.dart.cache;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element,
@@ skipping 235 matching lines @@
 
   /**
    * Add suggestions for all top level elements in the context
    * excluding those elemnents for which suggestions have already been added.
    */
   void _addNonImportedElementSuggestions(List<SearchMatch> matches,
       Set<LibraryElement> excludedLibs) {
     matches.forEach((SearchMatch match) {
       if (match.kind == MatchKind.DECLARATION) {
         Element element = match.element;
-        if (element.isPublic &&
+        if (element.context == context &&
+            element.isPublic &&
             !excludedLibs.contains(element.library) &&
             !_importedCompletions.contains(element.displayName)) {
           _addSuggestion(element, CompletionRelevance.LOW);
         }
       }
     });
   }
 
   /**
    * Add a suggestion for the given element.
@@ skipping 86 matching lines @@
   @override
   void visitFunctionTypeAliasElement(FunctionTypeAliasElement element) {
     cache._addSuggestion(element, CompletionRelevance.DEFAULT);
   }
 
   @override
   void visitTopLevelVariableElement(TopLevelVariableElement element) {
     cache._addSuggestion(element, CompletionRelevance.DEFAULT);
   }
 }