Check in codegen test expectations.

test/codegen/expect/language/getter_override3_test.js

+dart_library.library('language/getter_override3_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__getter_override3_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const getter_override3_test = Object.create(null);
+  let VoidTovoid = () => (VoidTovoid = dart.constFn(dart.definiteFunctionType(dart.void, [])))();
+  const _x = Symbol('_x');
+  getter_override3_test.A = class A extends core.Object {
+    new() {
+      this[_x] = 42;
+    }
+    set x(val) {
+      this[_x] = val;
+    }
+  };
+  getter_override3_test.B = class B extends getter_override3_test.A {
+    new() {
+      super.new();
+    }
+    get x() {
+      return this[_x];
+    }
+    set x(value) {
+      super.x = value;
+    }
+  };
+  getter_override3_test.main = function() {
+    let b = new getter_override3_test.B();
+    expect$.Expect.equals(42, b.x);
+    b.x = 21;
+    expect$.Expect.equals(21, b.x);
+  };
+  dart.fn(getter_override3_test.main, VoidTovoid());
+  // Exports:
+  exports.getter_override3_test = getter_override3_test;
+});