MD History: Implement search functionality.

chrome/browser/resources/md_history/history_toolbar.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.
 
 Polymer({
   is: 'history-toolbar',
   properties: {
     // Number of history items currently selected.
     count: {
       type: Number,
       value: 0,
       observer: 'changeToolbarView_'
     },
+
     // True if 1 or more history items are selected. When this value changes
     // the background colour changes.
     itemsSelected_: {
       type: Boolean,
       value: false,
       reflectToAttribute: true
+    },
+
+    // The search term associated with the current results shown. Also used to
+    // determine whether results need to be refreshed (i.e. if it changes).
+    searchTerm: {
+      type: String,
+      value: ''
     }
   },
 
   /**
    * Changes the toolbar background color depending on whether any history items
    * are currently selected.
    * @private
    */
   changeToolbarView_: function() {
     this.itemsSelected_ = this.count > 0;
   },
 
+  /**
+   * If the search term has changed reload for the new search.
+   */
+  onSearchTermSearch: function(searchTerm) {
+    if (searchTerm != this.searchTerm)
+      this.fire('refresh-results', {search: searchTerm});
+    this.searchTerm = searchTerm;
+  },
+
+  attached: function() {
+    this.async(function() {
+      this.searchFieldDelegate_ = new ToolbarSearchFieldDelegate(this);
+      this.$['search-input'].setDelegate(this.searchFieldDelegate_);
+    });
+  },
+
   onClearSelectionTap_: function() {
     this.fire('unselect-all');
   },
 
   /**
    * Relocates the user to the clear browsing data section of the settings page.
    * @private
    */
   onClearBrowsingDataTap_: function() {
     window.location.href = 'chrome://settings/clearBrowserData';
   },
 
   onDeleteTap_: function() {
     this.fire('delete-selected');
   },
 
   /**
    * If the user is a supervised user the delete button is not shown.
    * @private
    */
   deletingAllowed_: function() {
     return loadTimeData.getBoolean('allowDeletingHistory');
   },
 
   numberOfItemsSelected_: function(count) {
     return count > 0 ? loadTimeData.getStringF('itemsSelected', count) : '';
   }
 });
+
+/**
+ * @constructor
+ * @implements {SearchFieldDelegate}
+ * @param {!Object} toolbar This history-toolbar.
+ */
+function ToolbarSearchFieldDelegate(toolbar) {
+  this.toolbar_ = toolbar;
+}
+
+ToolbarSearchFieldDelegate.prototype = {
+  /** @override */
+  onSearchTermSearch: function(searchTerm) {
+    this.toolbar_.onSearchTermSearch(searchTerm);
+  }
+};