Prevent public session users from changing locale via settings

Changes to the locale made via the settings screen persist outside the
current session and affect e.g. the login screen. Public session users
should not be permitted to make such changes.

BUG=214904
TEST=Manual - public session cannot, regular user can change locale

Review URL: https://codereview.chromium.org/412583002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285091 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/options/language_options.html

@@ -28,7 +28,8 @@
       <div id="language-options-details">
         <h3 id="language-options-language-name"></h3>
 <if expr="os == 'win32' or chromeos">
-        <div class="language-options-contents">
+        <div id="language-options-ui-language-section"
+             class="language-options-contents">
           <button id="language-options-ui-language-button"
               i18n-content="displayInThisLanguage">
           </button>

chrome/browser/resources/options/language_options.js

@@ -253,6 +253,10 @@ cr.define('options', function() {
 
       $('language-confirm').onclick =
           OptionsPage.closeOverlay.bind(OptionsPage);
+
+      // Public session users cannot change the locale.
+      if (cr.isChromeOS && UIAccountTweaks.loggedInAsPublicAccount())
+        $('language-options-ui-language-section').hidden = true;
     },
 
     /**

chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.cc

@@ -25,6 +25,7 @@
 #include "chromeos/ime/component_extension_ime_manager.h"
 #include "chromeos/ime/extension_ime_util.h"
 #include "chromeos/ime/input_method_manager.h"
+#include "components/user_manager/user_type.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
@@ -199,9 +200,11 @@ void CrosLanguageOptionsHandler::SetApplicationLocale(
   Profile* profile = Profile::FromWebUI(web_ui());
   UserManager* user_manager = UserManager::Get();
 
-  // Only the primary user can change the locale.
+  // Secondary users and public session users cannot change the locale.
   user_manager::User* user = ProfileHelper::Get()->GetUserByProfile(profile);
-  if (user && user->email() == user_manager->GetPrimaryUser()->email()) {
+  if (user &&
+      user->email() == user_manager->GetPrimaryUser()->email() &&
+      user->GetType() != user_manager::USER_TYPE_PUBLIC_ACCOUNT) {
     profile->ChangeAppLocale(language_code,
                              Profile::APP_LOCALE_CHANGED_VIA_SETTINGS);
   }