[MD Bookmarks] Add UI for Material Bookmarks.

chrome/browser/resources/md_bookmarks/list.js

+// Copyright 2016 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.
+
+Polymer({
+  is: 'bookmarks-list',
+
+  properties: {
+    /** @type {BookmarkTreeNode} */
+    selectedNode: Object,
+  },
+
+  listeners: {
+    'toggle-menu': 'onToggleMenu_'
+  },
+
+  /**
+   * @param {Event} e
+   * @private
+   */
+  onToggleMenu_: function(e) {
+    var menu = /** @type {!CrActionMenuElement} */ (
+        this.$.dropdown);
+    menu.showAt(/** @type {!Element} */ (e.detail.target));
+  },
+
+  // TODO(jiaxi): change these dummy click event handlers later.
+  /** @private */
+  onEditTap_: function() {
+    this.closeDropdownMenu_();
+  },
+
+  /** @private */
+  onCopyURLTap_: function() {
+    this.closeDropdownMenu_();
+  },
+
+  /** @private */
+  onDeleteTap_: function() {
+    this.closeDropdownMenu_();
+  },
+
+  /** @private */
+  closeDropdownMenu_: function() {
+    var menu = /** @type {!CrActionMenuElement} */ (
+        this.$.dropdown);
+    menu.close();
+  }
+});