Prepare for decoupling analyzer ASTs from element model.

pkg/analyzer/test/utils.dart

Index: pkg/analyzer/test/utils.dart
diff --git a/pkg/analyzer/test/utils.dart b/pkg/analyzer/test/utils.dart
index be7e64dd95429e86da3ff8fe7c863eae70b3384e..03273c6668a9f48343a89b3562be113ed2e3ca9e 100644
--- a/pkg/analyzer/test/utils.dart
+++ b/pkg/analyzer/test/utils.dart
@@ -5,9 +5,11 @@
 library analyzer.test.utils;
 
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/resolution_accessors.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/generated/resolver.dart' show TypeProvider;
+import 'package:front_end/src/base/source.dart';
 import 'package:test/test.dart';
 
 /**
@@ -45,7 +47,8 @@ class AstFinder {
         return unitMember;
       }
     }
-    fail('No class named $className in ${unit.element.source}');
+    Source source = elementForCompilationUnit(unit).source;
+    fail('No class named $className in $source');
     return null;
   }