Use entities in CommonElements interface.

tests/compiler/dart2js/related_types.dart

 // Copyright (c) 2015, 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 related_types;
 
 import 'package:compiler/src/commandline_options.dart';
 import 'package:compiler/src/compiler.dart';
 import 'package:compiler/src/core_types.dart';
 import 'package:compiler/src/elements/resolution_types.dart';
@@ skipping 244 matching lines @@
 
   ResolutionDartType apply(Node node, [_]) {
     ResolutionDartType type = node.accept(this);
     if (type == null) {
       type = const ResolutionDynamicType();
     }
     return type;
   }
 
   @override
-  ResolutionDartType visitEquals(Send node, Node left, Node right, _) {
+  ResolutionInterfaceType visitEquals(Send node, Node left, Node right, _) {
     ResolutionDartType leftType = apply(left);
     ResolutionDartType rightType = apply(right);
     checkRelated(node, leftType, rightType);
     return commonElements.boolType;
   }
 
   @override
-  ResolutionDartType visitNotEquals(Send node, Node left, Node right, _) {
+  ResolutionInterfaceType visitNotEquals(Send node, Node left, Node right, _) {
     ResolutionDartType leftType = apply(left);
     ResolutionDartType rightType = apply(right);
     checkRelated(node, leftType, rightType);
     return commonElements.boolType;
   }
 
   @override
   ResolutionDartType visitIndex(Send node, Node receiver, Node index, _) {
     ResolutionDartType receiverType = apply(receiver);
     ResolutionDartType indexType = apply(index);
     ResolutionInterfaceType mapType = findMapType(receiverType);
     ResolutionDartType keyType = findMapKeyType(mapType);
     ResolutionDartType valueType = findMapValueType(mapType);
     checkRelated(index, keyType, indexType);
     return valueType;
   }
 
   @override
-  ResolutionDartType visitLiteralInt(LiteralInt node) {
+  ResolutionInterfaceType visitLiteralInt(LiteralInt node) {
     return commonElements.intType;
   }
 
   @override
-  ResolutionDartType visitLiteralString(LiteralString node) {
+  ResolutionInterfaceType visitLiteralString(LiteralString node) {
     return commonElements.stringType;
   }
 
   @override
-  ResolutionDartType visitLiteralBool(LiteralBool node) {
+  ResolutionInterfaceType visitLiteralBool(LiteralBool node) {
     return commonElements.boolType;
   }
 
   @override
   ResolutionDartType visitLiteralMap(LiteralMap node) {
     return elements.getType(node);
   }
 
   @override
   ResolutionDartType visitLiteralList(LiteralList node) {
@@ skipping 116 matching lines @@
   ClassElement findClass(ResolutionDartType type) => type.accept(this, null);
 
   @override
   ClassElement visitType(ResolutionDartType type, _) => null;
 
   @override
   ClassElement visitInterfaceType(ResolutionInterfaceType type, _) {
     return type.element;
   }
 }