Use entities in CommonElements interface.

tests/compiler/dart2js/type_checker_test.dart

 // Copyright (c) 2011, 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.
 
 import 'dart:async';
 
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 
 import 'package:compiler/src/elements/resolution_types.dart';
@@ skipping 53 matching lines @@
     testTypePromotionHints,
     testFunctionCall,
     testCascade,
     testAwait,
     testAsyncReturn
   ];
   asyncTest(() => Future.forEach(tests, (test) => setup(test)));
 }
 
 testSimpleTypes(MockCompiler compiler) {
-  checkType(ResolutionDartType type, String code) {
+  checkType(ResolutionInterfaceType type, String code) {
     Expect.equals(type, analyzeType(compiler, code));
   }
 
   checkType(compiler.commonElements.intType, "3");
   checkType(compiler.commonElements.boolType, "false");
   checkType(compiler.commonElements.boolType, "true");
   checkType(compiler.commonElements.stringType, "'hestfisk'");
 }
 
 Future testReturn(MockCompiler compiler) {
@@ skipping 2690 matching lines @@
   TreeElements elements = compiler.resolveNodeStatement(node, element);
   TypeCheckerVisitor checker =
       new TypeCheckerVisitor(compiler, elements, compiler.types);
   DiagnosticCollector collector = compiler.diagnosticCollector;
   collector.clear();
   checker.analyze(node, mustHaveType: false);
   generateOutput(compiler, text);
   compareWarningKinds(text, warnings, collector.warnings);
   compareWarningKinds(text, hints, collector.hints);
 }