ChromeOS: implement per-user time zone preferences.

chrome/browser/chromeos/policy/browser_policy_connector_chromeos.cc

Index: chrome/browser/chromeos/policy/browser_policy_connector_chromeos.cc
diff --git a/chrome/browser/chromeos/policy/browser_policy_connector_chromeos.cc b/chrome/browser/chromeos/policy/browser_policy_connector_chromeos.cc
index 1fd7393b3901408a43467f76d5f0bb8ae4329fa3..d16b8b46cac6ac69ac91900c0d5c320215acc245 100644
--- a/chrome/browser/chromeos/policy/browser_policy_connector_chromeos.cc
+++ b/chrome/browser/chromeos/policy/browser_policy_connector_chromeos.cc
@@ -19,6 +19,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/attestation/attestation_ca_client.h"
 #include "chrome/browser/chromeos/policy/active_directory_policy_manager.h"
 #include "chrome/browser/chromeos/policy/affiliated_cloud_policy_invalidator.h"
@@ -36,6 +37,7 @@
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/settings/device_settings_service.h"
 #include "chrome/browser/chromeos/settings/install_attributes.h"
+#include "chrome/browser/chromeos/system/timezone_util.h"
 #include "chrome/browser/policy/device_management_service_configuration.h"
 #include "chrome/common/pref_names.h"
 #include "chromeos/attestation/attestation_flow.h"
@@ -57,6 +59,7 @@
 #include "components/policy/core/common/proxy_policy_provider.h"
 #include "components/policy/proto/device_management_backend.pb.h"
 #include "components/prefs/pref_registry_simple.h"
+#include "components/prefs/pref_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "google_apis/gaia/gaia_auth_util.h"
 #include "net/url_request/url_request_context_getter.h"
@@ -342,8 +345,7 @@ void BrowserPolicyConnectorChromeOS::SetTimezoneIfPolicyAvailable() {
   if (chromeos::CrosSettings::Get()->GetString(chromeos::kSystemTimezonePolicy,
                                                &timezone) &&
       !timezone.empty()) {
-    chromeos::system::TimezoneSettings::GetInstance()->SetTimezoneFromID(
-        base::UTF8ToUTF16(timezone));
+    chromeos::system::SetSigninScreenTimezone(timezone, true);
   }
 }