Call preventDefault in all on-tap events that show a dialog.

chrome/browser/resources/settings/on_startup_page/startup_url_entry.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.
 
 /**
  * @fileoverview settings-startup-url-entry represents a UI component that
  * displayes a URL that is loaded during startup. It includes a menu that allows
  * the user to edit/remove the entry.
  */
 
@@ skipping 28 matching lines @@
     return cr.icon.getFavicon(url);
   },
 
   /** @private */
   onRemoveTap_: function() {
     this.$$('dialog[is=cr-action-menu]').close();
     settings.StartupUrlsPageBrowserProxyImpl.getInstance().removeStartupPage(
         this.model.modelIndex);
   },
 
-  /** @private */
-  onEditTap_: function() {
+  /**
+   * @param {!Event} e
+   * @private
+   */
+  onEditTap_: function(e) {
+    e.preventDefault();
     this.$$('dialog[is=cr-action-menu]').close();
     this.fire(settings.EDIT_STARTUP_URL_EVENT, this.model);
   },
 
   /** @private */
   onDotsTap_: function() {
     var actionMenu = /** @type {!CrActionMenuElement} */(
         this.$$('#menu').get());
     actionMenu.showAt(assert(this.$$('#dots')));
   },
 });