TBR Revert "Remove MemberMap in favor of HashMap"

pkg/analysis_server/lib/src/services/completion/dart/override_contributor.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.dart.override;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart'
     show CompletionSuggestion, CompletionSuggestionKind;
@@ skipping 21 matching lines @@
     }
     ClassDeclaration classDecl =
         targetId.getAncestor((p) => p is ClassDeclaration);
     if (classDecl == null) {
       return EMPTY_LIST;
     }
 
     // Generate a collection of inherited members
     ClassElement classElem = classDecl.element;
     InheritanceManager manager = new InheritanceManager(classElem.library);
-    Map<String, ExecutableElement> map =
-        manager.getMapOfMembersInheritedFromInterfaces(classElem);
+    MemberMap map = manager.getMapOfMembersInheritedFromInterfaces(classElem);
     List<String> memberNames = _computeMemberNames(map, classElem);
 
     // Build suggestions
     List<CompletionSuggestion> suggestions = <CompletionSuggestion>[];
     for (String memberName in memberNames) {
-      ExecutableElement element = map[memberName];
+      ExecutableElement element = map.get(memberName);
       // Gracefully degrade if the overridden element has not been resolved.
       if (element.returnType != null) {
         CompletionSuggestion suggestion =
             _buildSuggestion(request, targetId, element);
         if (suggestion != null) {
           suggestions.add(suggestion);
         }
       }
     }
     return suggestions;
@@ skipping 40 matching lines @@
         false);
     suggestion.element = protocol.convertElement(element);
     return suggestion;
   }
 
   /**
    * Return a list containing the names of all of the inherited but not
    * implemented members of the class represented by the given [element].
    * The [map] is used to find all of the members that are inherited.
    */
-  List<String> _computeMemberNames(
-      Map<String, ExecutableElement> map, ClassElement element) {
+  List<String> _computeMemberNames(MemberMap map, ClassElement element) {
     List<String> memberNames = <String>[];
-    for (String memberName in map.keys) {
+    int count = map.size;
+    for (int i = 0; i < count; i++) {
+      String memberName = map.getKey(i);
       if (!_hasMember(element, memberName)) {
         memberNames.add(memberName);
       }
     }
     return memberNames;
   }
 
   /**
    * If the target looks like a partial identifier inside a class declaration
    * then return that identifier, otherwise return `null`.
@@ skipping 19 matching lines @@
    * Return `true` if the given [classElement] directly declares a member with
    * the given [memberName].
    */
   bool _hasMember(ClassElement classElement, String memberName) {
     return classElement.getField(memberName) != null ||
         classElement.getGetter(memberName) != null ||
         classElement.getMethod(memberName) != null ||
         classElement.getSetter(memberName) != null;
   }
 }