Check in codegen test expectations.

test/codegen/expect/corelib/stopwatch2_test.js

Index: test/codegen/expect/corelib/stopwatch2_test.js
diff --git a/test/codegen/expect/corelib/stopwatch2_test.js b/test/codegen/expect/corelib/stopwatch2_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..b087b3ba76e04507070e5a77b0990d13221d5ebd
--- /dev/null
+++ b/test/codegen/expect/corelib/stopwatch2_test.js
@@ -0,0 +1,24 @@
+dart_library.library('corelib/stopwatch2_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__stopwatch2_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 stopwatch2_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  stopwatch2_test.main = function() {
+    let sw = new core.Stopwatch();
+    sw.start();
+    while (dart.notNull(sw.elapsedMilliseconds) < 2) {
+    }
+    sw.stop();
+    expect$.Expect.equals(sw.elapsedMicroseconds, sw.elapsed.inMicroseconds);
+    expect$.Expect.equals(sw.elapsedMilliseconds, sw.elapsed.inMilliseconds);
+  };
+  dart.fn(stopwatch2_test.main, VoidTodynamic());
+  // Exports:
+  exports.stopwatch2_test = stopwatch2_test;
+});