Add AnalysisContext.onResultInvalidated(descriptor).

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 582 matching lines @@
     return false;
   }
 
   @override
   bool isServerLibrary(Source librarySource) {
     fail("Unexpected invocation of isServerLibrary");
     return false;
   }
 
   @override
+  Stream<ResultChangedEvent> onResultChanged(ResultDescriptor descriptor) {
+    fail("Unexpected invocation of onResultChanged");
+    return null;
+  }
+
+  @override
   Stream<ComputedResult> onResultComputed(ResultDescriptor descriptor) {
     fail("Unexpected invocation of onResultComputed");
     return null;
   }
 
   @override
   CompilationUnit parseCompilationUnit(Source source) {
     fail("Unexpected invocation of parseCompilationUnit");
     return null;
   }
@@ skipping 65 matching lines @@
   bool validateCacheConsistency() {
     fail("Unexpected invocation of validateCacheConsistency");
     return false;
   }
 
   @override
   void visitContentCache(ContentCacheVisitor visitor) {
     fail("Unexpected invocation of visitContentCache");
   }
 }