Language settings: Fix Restart and Remove buttons shown at wrong times

chrome/browser/resources/settings/languages_page/languages_page.js

Index: chrome/browser/resources/settings/languages_page/languages_page.js
diff --git a/chrome/browser/resources/settings/languages_page/languages_page.js b/chrome/browser/resources/settings/languages_page/languages_page.js
index 803c0f9f0d7826b0a9bf79e13b34563a5887d1b7..eb79036bb957e463275fc93ea835d24b2ed0c1f9 100644
--- a/chrome/browser/resources/settings/languages_page/languages_page.js
+++ b/chrome/browser/resources/settings/languages_page/languages_page.js
@@ -138,14 +138,9 @@ Polymer({
     if (!languageState.language.supportsUI)
       return true;
 
-    // If the language already is the prospective UI language, it can't be unset
-    // if it is also the *actual* UI language, as we wouldn't know what other
-    // language to set as the prospective UI language.
-    if (languageState.language.code == navigator.language &&

[michaelpg, 2016/12/13 05:33:09]

Simplifying this because it leads to bugs and it's kind of silly to allow you to
uncheck "Show Chrome OS in this language".

-        (!prospectiveUILanguage ||
-         languageState.language.code == prospectiveUILanguage)) {
+    // Unchecking the currently chosen language doesn't make much sense.
+    if (languageState.language.code == prospectiveUILanguage)
       return true;
-    }
 
     // Otherwise, the prospective language can be changed to/from this language.
     return false;
@@ -166,11 +161,12 @@ Polymer({
    */
   onUILanguageChange_: function(e) {
     if (e.target.checked) {
-      this.languageHelper.setUILanguage(this.detailLanguage_.language.code);
+      this.languageHelper.setProspectiveUILanguage(
+          this.detailLanguage_.language.code);
     } else if (this.detailLanguage_.language.code ==
-        this.languageHelper.getProspectiveUILanguage()) {
+        this.languages.prospectiveUILanguage) {
       // Reset the chosen UI language to the actual UI language.
-      this.languageHelper.resetUILanguage();
+      this.languageHelper.resetProspectiveUILanguage();
     }
     /** @type {!CrActionMenuElement} */(this.$.menu.get()).close();
   },
@@ -356,17 +352,17 @@ Polymer({
    */
   isProspectiveUILanguage_: function(languageCode, prospectiveUILanguage) {
     assert(cr.isChromeOS || cr.isWindows);
-    return languageCode == this.languageHelper.getProspectiveUILanguage();
+    return languageCode == prospectiveUILanguage;
   },
 
 <if expr="chromeos or is_win">
    /**
+    * @param {string} prospectiveUILanguage
     * @return {string}
     * @private
     */
-  getProspectiveUILanguageName_: function() {
-    return this.languageHelper.getLanguage(
-        this.languageHelper.getProspectiveUILanguage()).displayName;
+  getProspectiveUILanguageName_: function(prospectiveUILanguage) {
+    return this.languageHelper.getLanguage(prospectiveUILanguage).displayName;
   },
 </if>
 
@@ -392,15 +388,12 @@ Polymer({
    * selected on Chrome OS and Windows.
    * @param {string} languageCode The language code identifying a language.
    * @param {string} prospectiveUILanguage The prospective UI language.
-   * @param {boolean} supportsUI Whether Chrome's UI can be shown in this
-   *     language.
    * @return {string} The class name for the language item.
    * @private
    */
-  getLanguageItemClass_: function(languageCode, prospectiveUILanguage,
-      supportsUI) {
+  getLanguageItemClass_: function(languageCode, prospectiveUILanguage) {
     if ((cr.isChromeOS || cr.isWindows) &&
-        this.isProspectiveUILanguage_(languageCode, prospectiveUILanguage)) {
+        languageCode == prospectiveUILanguage) {
       return 'selected';
     }
     return '';
@@ -415,7 +408,7 @@ Polymer({
    */
   isRestartRequired_: function(languageCode, prospectiveUILanguage) {
     return prospectiveUILanguage == languageCode &&
-        navigator.language != languageCode;
+        this.languageHelper.requiresRestart();
   },
 
   /**