ChromeOS NetworkScreenHandler should not call CheckAndResolveLocale on UI thread.

chrome/browser/chromeos/login/session/user_session_manager.cc

Index: chrome/browser/chromeos/login/session/user_session_manager.cc
diff --git a/chrome/browser/chromeos/login/session/user_session_manager.cc b/chrome/browser/chromeos/login/session/user_session_manager.cc
index 664b869d4ec2f2bc5fecd7cd4b13591bf8b27072..06b0ca649b4fe7e6fa21dab19f7f448f51153e61 100644
--- a/chrome/browser/chromeos/login/session/user_session_manager.cc
+++ b/chrome/browser/chromeos/login/session/user_session_manager.cc
@@ -374,7 +374,7 @@ void UserSessionManager::SetAppModeChromeClientOAuthInfo(
 bool UserSessionManager::RespectLocalePreference(
     Profile* profile,
     const user_manager::User* user,
-    scoped_ptr<locale_util::SwitchLanguageCallback> callback) const {
+    const locale_util::SwitchLanguageCallback& callback) const {
   // TODO(alemate): http://crbug.com/288941 : Respect preferred language list in
   // the Google user profile.
   if (g_browser_process == NULL)
@@ -442,10 +442,8 @@ bool UserSessionManager::RespectLocalePreference(
   // So input methods should be enabled somewhere.
   const bool enable_layouts =
       user_manager::UserManager::Get()->IsLoggedInAsGuest();
-  locale_util::SwitchLanguage(pref_locale,
-                              enable_layouts,
-                              false /* login_layouts_only */,
-                              callback.Pass());
+  locale_util::SwitchLanguage(
+      pref_locale, enable_layouts, false /* login_layouts_only */, callback);
 
   return true;
 }