Add cr-toggle-button to Chrome

ui/webui/resources/cr_elements/cr_events/cr-events.js

+/* 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-events` provides helpers for handling events in Chrome Polymer elements.
+ *
+ * Example:
+ *
+ *    <cr-events id="events"></cr-events>
+ *
+ * Usage:
+ *
+ *    this.$.events.forward(this.$.element, ['change']);
+ *
+ * @element cr-events
+ */
+Polymer({
+  /**
+   * Sets up an element to forward events across the shadow boundary, for events
+   * which normally stop at the root node (see http://goo.gl/WGMO9x).
+   * @param {!HTMLElement} element The element to forward events from.
+   * @param {!Array.<string>} events The events to forward.
+   */
+  forward: function(element, events) {
+    for (var i = 0; i < events.length; i++)
+      element.addEventListener(events[i], this.forwardEvent_);
+  },
+
+
+  /**
+   * Forwards events that don't automatically cross the shadow boundary
+   * if the event should bubble.
+   * @param {!Event} e The event to forward.
+   * @param {*} detail Data passed when initializing the event.
+   * @param {Node=} opt_sender Node that declared the handler.
+   * @private
+   */
+  forwardEvent_: function(e, detail, opt_sender) {
+    if (!e.bubbles)
+      return;
+
+    var node = e.path[e.path.length - 1];
+    if (node instanceof ShadowRoot) {
+      // Forward the event to the shadow host.
+      e.stopPropagation();
+      node.host.fire(e.type, detail, node.host, true, e.cancelable);
+    }
+  },
+});