Validate cache consistency asynchronously. Compute modification times of physical files in a separa…

pkg/analyzer/test/generated/engine_test.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 analyzer.test.generated.engine_test;
 
 import 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 684 matching lines @@
     fail("Unexpected invocation of shouldErrorsBeAnalyzed");
     return false;
   }
 
   @override
   void test_flushAstStructures(Source source) {
     fail("Unexpected invocation of test_flushAstStructures");
   }
 
   @override
-  bool validateCacheConsistency() {
-    fail("Unexpected invocation of validateCacheConsistency");
-    return false;
-  }
-
-  @override
   void visitContentCache(ContentCacheVisitor visitor) {
     fail("Unexpected invocation of visitContentCache");
   }
+
+  @override
+  CacheConsistencyValidator get cacheConsistencyValidator {
+    fail("Unexpected invocation of cacheConsistencyValidator");
+    return null;
+  }
 }