Fix send to this.

tests/compiler/dart2js/cpa_inference_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 '../../../sdk/lib/_internal/compiler/implementation/scanner/scannerlib.dart';
 import '../../../sdk/lib/_internal/compiler/implementation/source_file.dart';
 import '../../../sdk/lib/_internal/compiler/implementation/types/types.dart';
 
 import "parser_helper.dart";
@@ skipping 447 matching lines @@
       }
       main() {
         var x = new B().bar();
         x;
       }
       """;
   AnalysisResult result = analyze(source);
   result.checkNodeHasType('x', [result.base('B')]);
 }
 
+testSendToThis3() {
+  final String source = r"""
+      class A {
+        bar() => 42;
+        foo() => bar();
+      }
+      class B extends A {
+        bar() => "abc";
+      }
+      main() {
+        var x = new B().foo();
+        x;
+      }
+      """;
+  AnalysisResult result = analyze(source);
+  result.checkNodeHasType('x', [result.string]);
+}
+
 testConstructor() {
   final String source = r"""
       class A {
         var x, y, z;
         A(this.x, a) : y = a { z = 'abc'; }
       }
       main() {
         new A(42, 'abc');
         new A(true, null);
       }
@@ skipping 977 matching lines @@
   testFor2();
   testFor3();
   testToplevelVariable();
   testNonRecusiveFunction();
   testRecusiveFunction();
   testMutuallyRecusiveFunction();
   testSimpleSend();
   // testSendToClosureField();  // closures are not yet supported
   testSendToThis1();
   testSendToThis2();
+  testSendToThis3();
   testConstructor();
   testGetters();
   testSetters();
   testOptionalNamedParameters();
   testOptionalPositionalParameters();
   testListLiterals();
   testMapLiterals();
   testReturn();
   // testNoReturn(); // right now we infer the empty type instead of null
   testArithmeticOperators();
@@ skipping 16 matching lines @@
   testListHierarchy();
   testJsCall();
   testJsCallAugmentsSeenClasses();
   testIsCheck();
   testSeenClasses();
   testIntDoubleNum();
   testConcreteTypeToTypeMask();
   testSelectors();
   testMixins();
 }