Remove warnings from dart2js test-suite.

tests/compiler/dart2js/resolver_test.dart

 // Copyright (c) 2012, 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 "package:expect/expect.dart";
 import 'dart:async';
 import "package:async_helper/async_helper.dart";
 import 'dart:collection';
 
 import "../../../sdk/lib/_internal/compiler/implementation/resolution/resolution.dart";
 import "compiler_helper.dart";
 import "parser_helper.dart";
 
 import '../../../sdk/lib/_internal/compiler/implementation/dart_types.dart';
+import '../../../sdk/lib/_internal/compiler/implementation/elements/modelx.dart';
 
 Node buildIdentifier(String name) => new Identifier(scan(name));
 
 Node buildInitialization(String name) =>
   parseBodyCode('$name = 1',
       (parser, tokens) => parser.parseOptionallyInitializedIdentifier(tokens));
 
 createLocals(List variables) {
   var locals = [];
   for (final variable in variables) {
@@ skipping 581 matching lines @@
   compiler.resolver.resolve(fooElement);
 
   compareWarningKinds(
       script, [MessageKind.INVALID_ARGUMENTS], compiler.warnings);
   compareWarningKinds(script, [], compiler.errors);
 }
 
 testTopLevelFields() {
   MockCompiler compiler = new MockCompiler();
   compiler.parseScript("int a;");
-  VariableElement element = compiler.mainApp.find("a");
+  VariableElementX element = compiler.mainApp.find("a");
   Expect.equals(ElementKind.FIELD, element.kind);
   VariableDefinitions node = element.variables.parseNode(element, compiler);
   Identifier typeName = node.type.typeName;
   Expect.equals(typeName.source, 'int');
 
   compiler.parseScript("var b, c;");
-  VariableElement bElement = compiler.mainApp.find("b");
-  VariableElement cElement = compiler.mainApp.find("c");
+  VariableElementX bElement = compiler.mainApp.find("b");
+  VariableElementX cElement = compiler.mainApp.find("c");
   Expect.equals(ElementKind.FIELD, bElement.kind);
   Expect.equals(ElementKind.FIELD, cElement.kind);
   Expect.isTrue(bElement != cElement);
 
   VariableDefinitions bNode = bElement.variables.parseNode(bElement, compiler);
   VariableDefinitions cNode = cElement.variables.parseNode(cElement, compiler);
   Expect.equals(bNode, cNode);
   Expect.isNull(bNode.type);
   Expect.isTrue(bNode.modifiers.isVar());
 }
@@ skipping 375 matching lines @@
       }""";
   asyncTest(() => compileScript(script2).then((compiler) {
     expect(compiler,
         [MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS],
         [MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_CONSTRUCTOR,
          MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_CONSTRUCTOR,
          MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_FIELD,
          MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_FIELD]);
   }));
 }