Added a timezone policy and pyauto tests for it.

chrome/browser/policy/device_policy_cache.cc

 // Copyright (c) 2012 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/policy/device_policy_cache.h"
 
 #include <limits>
 #include <string>
 #include <vector>
 
@@ skipping 704 matching lines @@
            entry != container.start_up_urls().end();
            ++entry) {
         urls->Append(Value::CreateStringValue(*entry));
       }
       policies->Set(key::kDeviceStartUpUrls,
                     POLICY_LEVEL_MANDATORY,
                     POLICY_SCOPE_MACHINE,
                     urls);
     }
   }
+
+  if (policy.has_system_timezone()) {
+    if (policy.system_timezone().has_timezone()) {
+      policies->Set(key::kDeviceTimezone,
+                    POLICY_LEVEL_MANDATORY,
+                    POLICY_SCOPE_MACHINE,
+                    Value::CreateStringValue(
+                        policy.system_timezone().timezone()));
+    }
+  }
 }
 
 }  // namespace policy