Site Settings Desktop: Change how adding site exceptions work.

chrome/browser/resources/settings/site_settings/site_list.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.
 
 /**
  * @fileoverview
  * 'settings-site-list' shows a list of Allowed and Blocked sites for a given
  * category.
  */
 Polymer({
@@ skipping 154 matching lines @@
           if (allowExists)
             return;
           this.$.category.opened = true;
       }.bind(this));
     } else {
       this.$.category.opened = true;
     }
   },
 
   /**
-   * Makes sure the visibility is correct for this widget (e.g. hidden if the
-   * block list is empty).
+   * Makes sure the visibility is correct for this widget.
    * @private
    */
   updateCategoryVisibility_: function() {
-    this.$.category.hidden =
-        !this.showSiteList_(this.sites, this.categoryEnabled);
+    this.$.category.hidden = !this.showSiteList_(this.categoryEnabled);
   },
 
   /**
+   * A handler for the Add Site button.
+   * @private
+   */
+  onAddSiteTap_: function() {
+    var dialog = document.createElement('add-site-dialog');
+    dialog.category = this.category;
+    this.shadowRoot.appendChild(dialog);
+
+    dialog.open(this.categorySubtype);
+
+    dialog.addEventListener('iron-overlay-closed', function() {
+      dialog.remove();
+    });
+  },
+
+  /**
    * Handles the expanding and collapsing of the sites list.
    * @private
    */
   onToggle_: function(e) {
     if (this.$.category.opened)
       this.$.icon.icon = 'cr:expand-less';
     else
       this.$.icon.icon = 'cr:expand-more';
   },
 
@@ skipping 232 matching lines @@
   /**
    * Returns true if this widget is showing the allow list.
    * @private
    */
   isAllowList_: function() {
     return this.categorySubtype == settings.PermissionValues.ALLOW;
   },
 
   /**
    * Returns whether to show the site list.
-   * @param {Array} siteList The list of all sites to display for this category
-   *     subtype.
    * @param {boolean} toggleState The state of the global toggle for this
    *     category.
    * @private
    */
-  showSiteList_: function(siteList, toggleState) {
-    if (siteList.length == 0)
-      return false;
-
+  showSiteList_: function(toggleState) {
     // The Block list is only shown when the category is set to Allow since it
     // is redundant to also list all the sites that are blocked.
     if (this.isAllowList_())
       return true;
 
     return toggleState;
   },
 });