MD Settings: Checks the event target in the language tap event handler

chrome/browser/resources/settings/languages_page/languages_page.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-languages-page' is the settings page
  * for language and input method settings.
  */
 (function() {
 'use strict';
@@ skipping 38 matching lines @@
   },
 
   /** @override */
   created: function() {
     this.languageHelper_ = LanguageHelperImpl.getInstance();
   },
 
   /**
    * Handler for clicking a language on the main page, which selects the
    * language as the prospective UI language on Chrome OS and Windows.
-   * @param {!{model: !{item: !LanguageState}}} e
+   * @param {!Event} e The tap event.
    */
   onLanguageTap_: function(e) {
+    // Make sure the event comes from tapping the language itself and not the
+    // options menu trigger or menu items.
+    if (Polymer.dom(e).localTarget.className.includes('dropdown-'))

[Dan Beam, 2016/08/10 20:45:26]

why are you just checking that dropdown- exists in the class name?  this doesn't
seem right.  my-dropdown-thing would match this.

can we just use something other than class here to do the filtering?

[Moe, 2016/08/10 23:58:32]

Made this a regex. It should be a more precise matching now. what do you suggest
using instead of class names?

+      return;
+
     // Only change the UI language on platforms that allow it.
     if ((!cr.isChromeOS && !cr.isWindows) || loadTimeData.getBoolean('isGuest'))
       return;
 
     // Set the prospective UI language. This won't take effect until a restart.
-    if (e.model.item.language.supportsUI)
-      this.languageHelper_.setUILanguage(e.model.item.language.code);
+
+    var tapEvent = /** @type {!{model: !{item: !LanguageState}}} */(e);
+    if (tapEvent.model.item.language.supportsUI)
+      this.languageHelper_.setUILanguage(tapEvent.model.item.language.code);
   },
 
   /**
    * Handler for enabling or disabling spell check.
    * @param {!{target: Element, model: !{item: !LanguageState}}} e
    */
   onSpellCheckChange_: function(e) {
     this.languageHelper_.toggleSpellCheck(e.model.item.language.code,
                                           e.target.checked);
   },
@@ skipping 240 matching lines @@
    * HACK(michaelpg): This is necessary to show the list when navigating to
    * the sub-page. Remove this function when PolymerElements/neon-animation#60
    * is fixed.
    * @param {string} tagName Name of the element containing the <iron-list>.
    */
   forceRenderList_: function(tagName) {
     this.$$(tagName).$$('iron-list').fire('iron-resize');
   },
 });
 })();