Chrome OS: make language per user.

chrome/browser/chromeos/login/language_switch_menu.cc

Index: chrome/browser/chromeos/login/language_switch_menu.cc
diff --git a/chrome/browser/chromeos/login/language_switch_menu.cc b/chrome/browser/chromeos/login/language_switch_menu.cc
index 3d8bcbceb925c4cceb76ef3cdf9513c1e86041f1..c18d20da42d4925457a8c879dde0b1c298a28df1 100644
--- a/chrome/browser/chromeos/login/language_switch_menu.cc
+++ b/chrome/browser/chromeos/login/language_switch_menu.cc
@@ -78,8 +78,11 @@ void LanguageSwitchMenu::SetFirstLevelMenuWidth(int width) {
 
 // static
 void LanguageSwitchMenu::SwitchLanguage(const std::string& locale) {
-  // Save new locale.
   DCHECK(g_browser_process);
+  if (g_browser_process->GetApplicationLocale() == locale) {
+    return;
+  }
+  // Save new locale.
   PrefService* prefs = g_browser_process->local_state();
   // TODO(markusheintz): If the preference is managed and can not be changed by
   // the user, changing the language should be disabled in the UI.