refactor ContributionSorter to use new API

pkg/analysis_server/lib/src/services/completion/common_usage_computer.dart

 // Copyright (c) 2015, 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.relevance;
 
+import 'package:analysis_server/completion/completion_dart.dart';
 import 'package:analysis_server/src/protocol_server.dart' as protocol;
 import 'package:analysis_server/src/protocol_server.dart'
     show CompletionSuggestion, CompletionSuggestionKind;
 import 'package:analysis_server/src/services/completion/contribution_sorter.dart';
-import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
+import 'package:analysis_server/src/services/completion/dart_completion_manager.dart'
+    show DART_RELEVANCE_COMMON_USAGE;
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 
 part 'common_usage_generated.dart';
 
 /**
  * A computer for adjusting the relevance of completions computed by others
  * based upon common Dart usage patterns. This is a long-lived object
  * that should not maintain state between calls to it's [sort] method.
  */
 class CommonUsageComputer implements ContributionSorter {
   /**
    * A map of <library>.<classname> to an ordered list of method names,
    * field names, getter names, and named constructors.
    * The names are ordered from most relevant to least relevant.
    * Names not listed are considered equally less relevant than those listed.
    */
   Map<String, List<String>> selectorRelevance;
 
   CommonUsageComputer([this.selectorRelevance = defaultSelectorRelevance]);
 
   @override
-  void sort(DartCompletionRequest request) {
-    _update(request);
+  void sort(DartCompletionRequest request,
+      Iterable<CompletionSuggestion> suggestions) {
+    _update(request, suggestions);
   }
 
   /**
    * Adjusts the relevance based on the given completion context.
    * The compilation unit and completion node
    * in the given completion context may not be resolved.
    */
-  void _update(DartCompletionRequest request) {
+  void _update(DartCompletionRequest request,
+      Iterable<CompletionSuggestion> suggestions) {
     var visitor = new _BestTypeVisitor(request.target.entity);
     DartType type = request.target.containingNode.accept(visitor);
     if (type != null) {
       Element typeElem = type.element;
       if (typeElem != null) {
         LibraryElement libElem = typeElem.library;
         if (libElem != null) {
-          _updateInvocationRelevance(request, type, libElem);
+          _updateInvocationRelevance(request, type, libElem, suggestions);
         }
       }
     }
   }
 
   /**
    * Adjusts the relevance of all method suggestions based upon the given
    * target type and library.
    */
-  void _updateInvocationRelevance(
-      DartCompletionRequest request, DartType type, LibraryElement libElem) {
+  void _updateInvocationRelevance(DartCompletionRequest request, DartType type,
+      LibraryElement libElem, Iterable<CompletionSuggestion> suggestions) {
     String typeName = type.name;
     List<String> selectors = selectorRelevance['${libElem.name}.${typeName}'];
     if (selectors != null) {
-      for (CompletionSuggestion suggestion in request.suggestions) {
+      for (CompletionSuggestion suggestion in suggestions) {
         protocol.Element element = suggestion.element;
         if (element != null &&
             (element.kind == protocol.ElementKind.CONSTRUCTOR ||
                 element.kind == protocol.ElementKind.FIELD ||
                 element.kind == protocol.ElementKind.GETTER ||
                 element.kind == protocol.ElementKind.METHOD ||
                 element.kind == protocol.ElementKind.SETTER) &&
             suggestion.kind == CompletionSuggestionKind.INVOCATION &&
             suggestion.declaringType == typeName) {
           int index = selectors.indexOf(suggestion.completion);
@@ skipping 47 matching lines @@
   DartType visitPropertyAccess(PropertyAccess node) {
     if (node.propertyName == entity) {
       Expression target = node.realTarget;
       if (target != null) {
         return target.bestType;
       }
     }
     return null;
   }
 }