MD WebUI: Pull 'X selected' toolbar overlay from History into shared element

ui/webui/resources/cr_elements/cr_toolbar/cr_toolbar_selection_overlay.js

+// Copyright 2017 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 Element which displays the number of selected items with
+ * Cancel/Delete buttons, designed to be used as an overlay on top of
+ * <cr-toolbar>. See <history-toolbar> for an example usage.
+ */
+
+Polymer({
+  is: 'cr-toolbar-selection-overlay',
+
+  properties: {
+    deleteLabel: String,
+
+    cancelLabel: String,
+
+    selectionLabel: String,
+  },
+
+  /** @private */
+  onClearSelectionTap_: function() {
+    this.fire('clear-selected-items');
+  },
+
+  /** @private */
+  onDeleteTap_: function() {

[Dan Beam, 2017/04/11 00:39:01]

nit: just name this deleteSelectedItems() and make public so we're not calling a
private method from tests?

[tsergeant, 2017/04/11 01:16:20]

Done, although the method being called from tests is in history_toolbar.js

+    this.fire('delete-selected-items');
+  },
+});