Cleanup warnings in unit tests.

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 "package:compiler/implementation/resolution/resolution.dart";
@@ skipping 296 matching lines @@
           new Message(MessageKind.DUPLICATE_DEFINITION, {'name': 'foo'}, false),
           compiler.errors[0].message);
     })], (f) => f());
 }
 
 
 Future testLocalsTwo() {
   return MockCompiler.create((MockCompiler compiler) {
     ResolverVisitor visitor = compiler.resolverVisitor();
     Node tree = parseStatement("if (true) { var a = 1; var b = 2; }");
-    Element element = visitor.visit(tree);
+    ResolutionResult element = visitor.visit(tree);
     Expect.equals(null, element);
     MethodScope scope = visitor.scope;
     Expect.equals(0, scope.elements.length);
     Expect.equals(2, map(visitor).length);
 
     List<Element> elements = new List<Element>.from(map(visitor).values);
     Expect.notEquals(elements[0], elements[1]);
   });
 }
 
 Future testLocalsThree() {
   return MockCompiler.create((MockCompiler compiler) {
     ResolverVisitor visitor = compiler.resolverVisitor();
     Node tree = parseStatement("{ var a = 1; if (true) { a; } }");
-    Element element = visitor.visit(tree);
+    ResolutionResult element = visitor.visit(tree);
     Expect.equals(null, element);
     MethodScope scope = visitor.scope;
     Expect.equals(0, scope.elements.length);
     Expect.equals(3, map(visitor).length);
     List<Element> elements = map(visitor).values.toList();
     Expect.equals(elements[0], elements[1]);
   });
 }
 
 Future testLocalsFour() {
   return MockCompiler.create((MockCompiler compiler) {
     ResolverVisitor visitor = compiler.resolverVisitor();
     Node tree = parseStatement("{ var a = 1; if (true) { var a = 1; } }");
-    Element element = visitor.visit(tree);
+    ResolutionResult element = visitor.visit(tree);
     Expect.equals(null, element);
     MethodScope scope = visitor.scope;
     Expect.equals(0, scope.elements.length);
     Expect.equals(2, map(visitor).length);
     List<Element> elements = map(visitor).values.toList();
     Expect.notEquals(elements[0], elements[1]);
   });
 }
 
 Future testLocalsFive() {
   return MockCompiler.create((MockCompiler compiler) {
     ResolverVisitor visitor = compiler.resolverVisitor();
     If tree =
         parseStatement("if (true) { var a = 1; a; } else { var a = 2; a;}");
-    Element element = visitor.visit(tree);
+    ResolutionResult element = visitor.visit(tree);
     Expect.equals(null, element);
     MethodScope scope = visitor.scope;
     Expect.equals(0, scope.elements.length);
     Expect.equals(6, map(visitor).length);
 
     Block thenPart = tree.thenPart;
     List statements1 = thenPart.statements.nodes.toList();
     Node def1 = statements1[0].definitions.nodes.head;
     Node id1 = statements1[1].expression;
     Expect.equals(visitor.registry.mapping[def1],
@@ skipping 697 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]);
   }));
 }