Check in codegen test expectations.

test/codegen/expect/language/interface_constants_test.js

+dart_library.library('language/interface_constants_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__interface_constants_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 interface_constants_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  interface_constants_test.Constants = class Constants extends core.Object {};
+  interface_constants_test.Constants.FIVE = 5;
+  interface_constants_test.InterfaceConstantsTest = class InterfaceConstantsTest extends core.Object {
+    new() {
+    }
+    static testMain() {
+      expect$.Expect.equals(5, interface_constants_test.Constants.FIVE);
+    }
+  };
+  dart.setSignature(interface_constants_test.InterfaceConstantsTest, {
+    constructors: () => ({new: dart.definiteFunctionType(interface_constants_test.InterfaceConstantsTest, [])}),
+    statics: () => ({testMain: dart.definiteFunctionType(dart.void, [])}),
+    names: ['testMain']
+  });
+  interface_constants_test.main = function() {
+    interface_constants_test.InterfaceConstantsTest.testMain();
+  };
+  dart.fn(interface_constants_test.main, VoidTodynamic());
+  // Exports:
+  exports.interface_constants_test = interface_constants_test;
+});