Add cr-checkbox to Chrome

ui/webui/resources/cr_elements/cr_checkbox/cr_checkbox.js

Index: ui/webui/resources/cr_elements/cr_checkbox/cr_checkbox.js
diff --git a/ui/webui/resources/cr_elements/cr_checkbox/cr_checkbox.js b/ui/webui/resources/cr_elements/cr_checkbox/cr_checkbox.js
new file mode 100644
index 0000000000000000000000000000000000000000..4011c010ef042f8f68527c6707fea285a7be2539
--- /dev/null
+++ b/ui/webui/resources/cr_elements/cr_checkbox/cr_checkbox.js
@@ -0,0 +1,56 @@
+/* Copyright 2015 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file. */
+
+/**
+ * @fileoverview
+ * `cr-checkbox` is a button that can be either checked or unchecked. User
+ * can tap the checkbox to check or uncheck it. Usually you use checkboxes
+ * to allow user to select multiple options from a set. If you have a single
+ * ON/OFF option, avoid using a single checkbox and use `cr-toggle-button`
+ * instead.
+ *
+ * Example:
+ *     <cr-checkbox></cr-checkbox>
+ *     <cr-checkbox checked></cr-checkbox>
+ *
+ * @element cr-checkbox
+ */
+Polymer({
+  publish: {
+    /**
+     * Gets or sets the state. `true` is checked and `false` is unchecked.
+     *
+     * @attribute checked
+     * @type boolean
+     * @default false
+     */
+    checked: {value: false, reflect: true},
+
+    /**
+     * The label for the checkbox.
+     *
+     * @attribute label
+     * @type string
+     * @default ''
+     */
+    label: '',
+
+    /**
+     * If true, the user cannot interact with this element.
+     *
+     * @attribute disabled
+     * @type boolean
+     * @default false
+     */
+    disabled: {value: false, reflect: true},
+  },
+
+  toggle: function() {
+    this.$.checkbox.toggle();
+  },
+
+  ready: function() {
+    this.$.events.forward(this.$.checkbox, ['change']);
+  },
+});