WebUI: cr-search-field: Remove delegation pattern, use simple event instead.

chrome/test/data/webui/md_history/history_toolbar_test.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.
 
 cr.define('md_history.history_toolbar_test', function() {
   function registerTests() {
     suite('history-toolbar', function() {
       var app;
       var element;
       var toolbar;
@@ skipping 31 matching lines @@
         });
       });
 
       test('search term gathered correctly from toolbar', function(done) {
         app.queryingDisabled_ = false;
         registerMessageCallback('queryHistory', this, function (info) {
           assertEquals(info[0], 'Test');
           done();
         });
 
-        toolbar.onSearch('Test');
+        toolbar.$$('cr-toolbar').fire('search-changed', 'Test');
       });
 
       teardown(function() {
         element.historyData_ = [];
         element.searchedTerm = '';
         registerMessageCallback('queryHistory', this, undefined);
         toolbar.count = 0;
       });
     });
   }
   return {
     registerTests: registerTests
   };
 });