MD WebUI: Add shared cr-toolbar element

ui/webui/resources/cr_elements/cr_toolbar/cr_toolbar_search_field.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.
+
+// TODO(tsergeant): Add tests for cr-toolbar-search-field.
+Polymer({
+  is: 'cr-toolbar-search-field',
+
+  behaviors: [CrSearchFieldBehavior],
+
+  properties: {
+    narrow: {
+      type: Boolean,
+      reflectToAttribute: true,
+    },
+
+    // Prompt text to display in the search field.
+    label: String,
+
+    // Tooltip to display on the clear search button.
+    clearLabel: String,
+  },
+
+  listeners: {
+    'tap': 'showSearch_',
+  },
+
+  /** @private */
+  onInputBlur_: function() {
+    if (!this.hasSearchText)
+      this.showingSearch = false;
+  },
+
+  /**
+   * @param {Event} e
+   * @private
+   */
+  showSearch_: function(e) {
+    if (e.target != this.$.clearSearch)
+      this.showingSearch = true;
+  },
+
+  /**
+   * @param {Event} e
+   * @private
+   */
+  hideSearch_: function(e) {
+    this.showingSearch = false;
+    e.stopPropagation();
+  }
+});