Check in codegen test expectations.

test/codegen/expect/language/double_to_string_as_precision3_test.js

Index: test/codegen/expect/language/double_to_string_as_precision3_test.js
diff --git a/test/codegen/expect/language/double_to_string_as_precision3_test.js b/test/codegen/expect/language/double_to_string_as_precision3_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..32179766a22fd5f4412e1fad768490a4fcf1438c
--- /dev/null
+++ b/test/codegen/expect/language/double_to_string_as_precision3_test.js
@@ -0,0 +1,23 @@
+dart_library.library('language/double_to_string_as_precision3_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__double_to_string_as_precision3_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 double_to_string_as_precision3_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  double_to_string_as_precision3_test.main = function() {
+    expect$.Expect.equals("0.000555000000000000046248", 0.000555[dartx.toStringAsPrecision](21));
+    expect$.Expect.equals(0.000555, 0.000555);
+    expect$.Expect.equals("5.54999999999999980179e-7", 5.55e-7[dartx.toStringAsPrecision](21));
+    expect$.Expect.equals(5.55e-7, 5.55e-7);
+    expect$.Expect.equals("-5.54999999999999980179e-7", (-5.55e-7)[dartx.toStringAsPrecision](21));
+    expect$.Expect.equals(-5.55e-7, -5.55e-7);
+  };
+  dart.fn(double_to_string_as_precision3_test.main, VoidTodynamic());
+  // Exports:
+  exports.double_to_string_as_precision3_test = double_to_string_as_precision3_test;
+});