remove duplicate completion suggestions

pkg/analysis_server/lib/src/services/completion/dart_completion_manager.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;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/completion/arglist_computer.dart';
@@ skipping 60 matching lines @@
   final DartCompletionCache cache;
   List<DartCompletionComputer> computers;
   CommonUsageComputer commonUsageComputer;
 
   DartCompletionManager(
       AnalysisContext context, this.searchEngine, Source source, this.cache,
       [this.computers, this.commonUsageComputer])
       : super(context, source) {
     if (computers == null) {
       computers = [
+        // LocalComputer before ImportedComputer
+        // because local suggestions take precedence
+        new LocalComputer(),
+        new ImportedComputer(),
         new KeywordComputer(),
-        new LocalComputer(),
         new ArgListComputer(),
         new CombinatorComputer(),
-        new ImportedComputer(),
         new InvocationComputer()
       ];
     }
     if (commonUsageComputer == null) {
       commonUsageComputer = new CommonUsageComputer();
     }
   }
 
   /**
    * Create a new initialized Dart source completion manager
@@ skipping 265 matching lines @@
             parameterNames: suggestion.parameterNames,
             parameterTypes: suggestion.parameterTypes,
             requiredParameterCount: suggestion.requiredParameterCount,
             hasNamedParameters: suggestion.hasNamedParameters,
             returnType: suggestion.returnType,
             element: suggestion.element);
       }
     }
   }
 }