Check in codegen test expectations.

test/codegen/expect/lib/math/pi_test.js

+dart_library.library('lib/math/pi_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__pi_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const math = dart_sdk.math;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const pi_test = Object.create(null);
+  let __Tovoid = () => (__Tovoid = dart.constFn(dart.definiteFunctionType(dart.void, [], [dart.dynamic])))();
+  pi_test.known_bad_seeds = dart.constList([50051, 55597, 59208], core.int);
+  pi_test.main = function(args) {
+    if (args === void 0) args = null;
+    let seed = -1;
+    if (args != null && dart.test(dart.dsend(dart.dload(args, 'length'), '>', 0))) {
+      seed = core.int.parse(core.String._check(dart.dindex(args, 0)));
+    } else {
+      let seed_prng = math.Random.new();
+      while (seed == -1) {
+        seed = seed_prng.nextInt(1 << 16);
+        if (dart.test(pi_test.known_bad_seeds[dartx.contains](seed))) {
+          seed = -1;
+        }
+      }
+    }
+    core.print(dart.str`pi_test seed: ${seed}`);
+    let prng = math.Random.new(seed);
+    let outside = 0;
+    let inside = 0;
+    for (let i = 0; i < 600000; i++) {
+      let x = prng.nextDouble();
+      let y = prng.nextDouble();
+      if (dart.notNull(x) * dart.notNull(x) + dart.notNull(y) * dart.notNull(y) < 1.0) {
+        inside++;
+      } else {
+        outside++;
+      }
+    }
+    let pie = 4.0 * (inside / (inside + outside));
+    core.print(dart.str`${pie}`);
+    expect$.Expect.isTrue(math.PI - 0.009 < pie && pie < math.PI + 0.009);
+  };
+  dart.fn(pi_test.main, __Tovoid());
+  // Exports:
+  exports.pi_test = pi_test;
+});