Don't call deprecated "isPotentiallyMutated..." API from analysis server.

pkg/analysis_server/lib/src/status/validator.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 analysis_server.src.status.validator;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 690 matching lines @@
           (VariableElement element) =>
               element.isConst ? 'a const $kind' : 'a non-const $kind');
     }
     if (expected.isFinal != actual.isFinal) {
       _writeMismatch(
           expected,
           actual,
           (VariableElement element) =>
               element.isFinal ? 'a final $kind' : 'a non-final $kind');
     }
-    if (expected.isPotentiallyMutatedInClosure !=
-        actual.isPotentiallyMutatedInClosure) {
-      _writeMismatch(
-          expected,
-          actual,
-          (VariableElement element) => element.isPotentiallyMutatedInClosure
-              ? 'a $kind that is potentially mutated in a closure'
-              : 'a $kind that is not mutated in a closure');
-    }
-    if (expected.isPotentiallyMutatedInScope !=
-        actual.isPotentiallyMutatedInScope) {
-      _writeMismatch(
-          expected,
-          actual,
-          (VariableElement element) => element.isPotentiallyMutatedInScope
-              ? 'a $kind that is potentially mutated in its scope'
-              : 'a $kind that is not mutated in its scope');
-    }
     if (expected.isStatic != actual.isStatic) {
       _writeMismatch(
           expected,
           actual,
           (VariableElement element) =>
               element.isStatic ? 'a static $kind' : 'an instance $kind');
     }
     //
     // Compare children.
     //
@@ skipping 1039 matching lines @@
    * Determine whether or not there is any interesting difference between the
    * original and cloned values.
    */
   void _performComparison() {
     StringBuffer buffer = new StringBuffer();
     if (!_compareObjects(cloneValue, originalValue, buffer)) {
       description = buffer.toString();
     }
   }
 }