MD Settings: Allow deleting read-only content setting exceptions.

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.
 
 /**
  * Enumeration mapping all possible controlled-by values for exceptions to
  * icons.
  * @enum {string}
  */
 var iconControlledBy = {
@@ skipping 476 matching lines @@
 
     if (item.incognito)
       return loadTimeData.getString('incognitoSite');
     return item.embeddingDisplayName;
   },
 
   /**
    * @param {!{model: !{item: !SiteException}}} e
    * @private
    */
+  onResetButtonTap_: function(e) {
+    // Trigger same logic as opening the menu and choosing the Reset item.
+    this.actionMenuSite_ = e.model.item;
+    this.onResetTap_();

[dschuyler, 2017/03/22 18:33:08]

It looks like only
this.onActionMenuActivate_(settings.PermissionValues.DEFAULT);
is necessary?
I'm not clear on why we'd call this.closeActionMenu_(). I suppose it's probably
harmless and would be fine if it were really hard to avoid that code path, but
it looks easy to avoid that path (though maybe I'm missing something?).

[tommycli, 2017/03/22 21:05:37]

Done.

+  },
+
+  /**
+   * @param {!{model: !{item: !SiteException}}} e
+   * @private
+   */
   onShowActionMenuTap_: function(e) {
     this.actionMenuSite_ = e.model.item;
     /** @type {!CrActionMenuElement} */ (
         this.$$('dialog[is=cr-action-menu]')).showAt(
             /** @type {!Element} */ (
                 Polymer.dom(/** @type {!Event} */ (e)).localTarget));
   },
 
   /** @private */
   closeActionMenu_: function() {
     this.actionMenuSite_ = null;
     var actionMenu = /** @type {!CrActionMenuElement} */ (
         this.$$('dialog[is=cr-action-menu]'));
     if (actionMenu.open)
       actionMenu.close();
   },
 });