Don't remove indexing operations on potential source changes.

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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.engine_test;
 
 import 'dart:async';
@@ skipping 6132 matching lines @@
   Future<CompilationUnit> computeResolvedCompilationUnitAsync(Source source,
       Source librarySource) {
     fail("Unexpected invocation of getResolvedCompilationUnitFuture");
     return null;
   }
   @override
   void dispose() {
     fail("Unexpected invocation of dispose");
   }
   @override
-  CompilationUnit ensureAnyResolvedDartUnit(Source source) {
-    fail("Unexpected invocation of ensureAnyResolvedDartUnit");
+  List<CompilationUnit> ensureResolvedDartUnits(Source source) {
+    fail("Unexpected invocation of ensureResolvedDartUnits");
     return null;
   }
   @override
   bool exists(Source source) {
     fail("Unexpected invocation of exists");
     return false;
   }
   @override
   CompilationUnitElement getCompilationUnitElement(Source unitSource,
       Source librarySource) {
@@ skipping 1042 matching lines @@
   bool exists() => true;
 }
 
 
 class _UniversalCachePartitionTest_test_setMaxCacheSize implements
     CacheRetentionPolicy {
   @override
   RetentionPriority getAstPriority(Source source, SourceEntry sourceEntry) =>
       RetentionPriority.LOW;
 }