[test] Add performance test for closures.

test/js-perf-test/Closures/closures.js

Index: test/js-perf-test/Closures/closures.js
diff --git a/test/js-perf-test/Closures/closures.js b/test/js-perf-test/Closures/closures.js
new file mode 100644
index 0000000000000000000000000000000000000000..38161a4d7f2459e59a1c0ced67b307768b104415
--- /dev/null
+++ b/test/js-perf-test/Closures/closures.js
@@ -0,0 +1,43 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+new BenchmarkSuite('Closures', [1000], [
+  new Benchmark('ShortLivingClosures', false, false, 0,
+    ShortLivingClosures, ShortLivingClosuresSetup, ShortLivingClosuresTearDown)
+]);
+
+// ----------------------------------------------------------------------------
+
+
+// The pattern is this example is very common in Node.js.
+var fs = {
+  readFile: function(filename, cb) {
+    cb(null, {length: 12});
+  }
+};
+
+
+function printLength (filename) {
+  fs.readFile(filename, foo);
+
+  function foo (err, buf)  {
+    if (err) return;
+    for (var j = 0; j<1000; j++) {
+      // Do some work to make the optimization actually worth while
+      buf.length++;
+    }
+    return (buf.length);
+  }
+}
+
+
+function ShortLivingClosuresSetup() {}
+
+function ShortLivingClosures() {
+  result = printLength('foo_bar.js');
+}
+
+function ShortLivingClosuresTearDown() {
+  return result == 1012;
+}