Fixes bug where clock button wasn't updating in response to a timezone

chrome/browser/chromeos/status/timezone_clock_updater.cc

Index: chrome/browser/chromeos/status/timezone_clock_updater.cc
diff --git a/chrome/browser/chromeos/status/timezone_clock_updater.cc b/chrome/browser/chromeos/status/timezone_clock_updater.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fe6c0c6d8f9623cab526cb46ba716818e6cd3dc2
--- /dev/null
+++ b/chrome/browser/chromeos/status/timezone_clock_updater.cc
@@ -0,0 +1,21 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/status/timezone_clock_updater.h"
+
+#include "chrome/browser/chromeos/status/clock_menu_button.h"
+#include "chrome/browser/chromeos/system/timezone_settings.h"
+
+TimezoneClockUpdater::TimezoneClockUpdater(ClockMenuButton* button)
+    : button_(button) {
+  chromeos::system::TimezoneSettings::GetInstance()->AddObserver(this);
+}
+
+TimezoneClockUpdater::~TimezoneClockUpdater() {
+  chromeos::system::TimezoneSettings::GetInstance()->RemoveObserver(this);
+}
+
+void TimezoneClockUpdater::TimezoneChanged(const icu::TimeZone& timezone) {
+  button_->UpdateText();
+}