Add Collections perf tests to v8 public repo.

test/perf-test/Collections/weakset.js

+// Copyright 2014 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.
+
+
+var SetBenchmark = new BenchmarkSuite('WeakSet', [1000], [
+  new Benchmark('Add', false, false, 0, WeakSetAdd),
+  new Benchmark('Has', false, false, 0, WeakSetHas, WeakSetSetup,
+      WeakSetTearDown),
+  new Benchmark('Delete', false, false, 0, WeakSetDelete, WeakSetSetup,
+      WeakSetTearDown),
+]);
+
+
+var ws;
+var N = 10;
+var keys = [];
+
+
+for (var i = 0; i < N * 2; i++) {
+  keys[i] = {};
+}
+
+
+function WeakSetSetup() {
+  ws = new WeakSet;
+  for (var i = 0; i < N; i++) {
+    ws.add(keys[i]);
+  }
+}
+
+
+function WeakSetTearDown() {
+  ws = null;
+}
+
+
+function WeakSetAdd() {
+  WeakSetSetup();
+  WeakSetTearDown();
+}
+
+
+function WeakSetHas() {
+  for (var i = 0; i < N; i++) {
+    if (!ws.has(keys[i])) {
+      throw new Error();
+    }
+  }
+  for (var i = N; i < 2 * N; i++) {
+    if (ws.has(keys[i])) {
+      throw new Error();
+    }
+  }
+}
+
+
+function WeakSetDelete() {
+  // This is run more than once per setup so we will end up deleting items
+  // more than once. Therefore, we do not the return value of delete.
+  for (var i = 0; i < N; i++) {
+    ws.delete(keys[i]);
+  }
+}