ChromeOS: implement per-user time zone preferences.

chrome/browser/chromeos/login/wizard_controller.cc

Index: chrome/browser/chromeos/login/wizard_controller.cc
diff --git a/chrome/browser/chromeos/login/wizard_controller.cc b/chrome/browser/chromeos/login/wizard_controller.cc
index 0d52be1bffebc54f6a75ed4d06ca172f3fadf56c..6c8d0be8067938ac5214ddab5e2bc839c4453005 100644
--- a/chrome/browser/chromeos/login/wizard_controller.cc
+++ b/chrome/browser/chromeos/login/wizard_controller.cc
@@ -62,6 +62,7 @@
 #include "chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/system/device_disabling_manager.h"
+#include "chrome/browser/chromeos/system/timezone_util.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/metrics/metrics_reporting_state.h"
 #include "chrome/browser/profiles/profile.h"
@@ -1435,9 +1436,7 @@ void WizardController::OnTimezoneResolved(
   if (!timezone->timeZoneId.empty()) {
     VLOG(1) << "Resolve TimeZone: setting timezone to '" << timezone->timeZoneId
             << "'";
-
-    system::TimezoneSettings::GetInstance()->SetTimezoneFromID(
-        base::UTF8ToUTF16(timezone->timeZoneId));
+    chromeos::system::SetSystemAndSigninScreenTimezone(timezone->timeZoneId);
   }
 }