Rename KernelWorldBuilder to KernelElementBuilder

tests/compiler/dart2js/serialization/test_helper.dart

Index: tests/compiler/dart2js/serialization/test_helper.dart
diff --git a/tests/compiler/dart2js/serialization/test_helper.dart b/tests/compiler/dart2js/serialization/test_helper.dart
index bb6c40cc82d60c8e9ca70a7b56b8629b568c4f46..8de7ba2a3fa782f9ec9741bcdc2bdbb897d2b5e7 100644
--- a/tests/compiler/dart2js/serialization/test_helper.dart
+++ b/tests/compiler/dart2js/serialization/test_helper.dart
@@ -14,7 +14,7 @@ import 'package:compiler/src/elements/entities.dart';
 import 'package:compiler/src/elements/resolution_types.dart';
 import 'package:compiler/src/elements/types.dart';
 import 'package:compiler/src/kernel/elements.dart';
-import 'package:compiler/src/kernel/world_builder.dart';
+import 'package:compiler/src/kernel/element_map.dart';
 import 'package:compiler/src/serialization/equivalence.dart';
 import 'package:compiler/src/util/util.dart';
 import 'package:expect/expect.dart';
@@ -645,7 +645,7 @@ class KernelEquivalence {
   Set<Pair<ClassEntity, ClassEntity>> assumedMixinApplications =
       new Set<Pair<ClassEntity, ClassEntity>>();
 
-  KernelEquivalence(KernelWorldBuilder builder)
+  KernelEquivalence(KernelToElementMap builder)
       : testing = new WorldDeconstructionForTesting(builder);
 
   TestStrategy get defaultStrategy => new TestStrategy(