Remove Element.users support.

pkg/analyzer/lib/src/generated/element_resolver.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 engine.resolver.element_resolver;
 
 import 'dart:collection';
 
 import 'ast.dart';
 import 'element.dart';
@@ skipping 605 matching lines @@
     }
     staticElement = _convertSetterToGetter(staticElement);
     propagatedElement = _convertSetterToGetter(propagatedElement);
     //
     // Record the results.
     //
     methodName.staticElement = staticElement;
     methodName.propagatedElement = propagatedElement;
     ArgumentList argumentList = node.argumentList;
     if (staticElement != null) {
-      staticElement.addUser(_resolver.enclosingFunction);
       List<ParameterElement> parameters =
           _computeCorrespondingParameters(argumentList, staticElement);
       if (parameters != null) {
         argumentList.correspondingStaticParameters = parameters;
       }
     }
     if (propagatedElement != null) {
-      propagatedElement.addUser(_resolver.enclosingFunction);
       List<ParameterElement> parameters =
           _computeCorrespondingParameters(argumentList, propagatedElement);
       if (parameters != null) {
         argumentList.correspondingPropagatedParameters = parameters;
       }
     }
     //
     // Then check for error conditions.
     //
     ErrorCode errorCode = _checkForInvocationError(target, true, staticElement);
@@ skipping 2480 matching lines @@
   @override
   Element get staticElement => null;
 
   @override
   accept(AstVisitor visitor) => null;
 
   @override
   void visitChildren(AstVisitor visitor) {
   }
 }