ChromeOS: Add SystemTimezoneAutomaticDetection policy.

chrome/browser/chromeos/policy/device_policy_decoder_chromeos.cc

Index: chrome/browser/chromeos/policy/device_policy_decoder_chromeos.cc
diff --git a/chrome/browser/chromeos/policy/device_policy_decoder_chromeos.cc b/chrome/browser/chromeos/policy/device_policy_decoder_chromeos.cc
index 3bc77ada84d748b2e57f02efe20948564a47cd02..6ae73c262f55cc10bdc4d1e9efa6dffad5dc996d 100644
--- a/chrome/browser/chromeos/policy/device_policy_decoder_chromeos.cc
+++ b/chrome/browser/chromeos/policy/device_policy_decoder_chromeos.cc
@@ -882,6 +882,17 @@ void DecodeGenericPolicies(const em::ChromeDeviceSettingsProto& policy,
                   POLICY_SCOPE_MACHINE, POLICY_SOURCE_CLOUD, whitelist,
                   nullptr);
   }
+
+  if (policy.has_system_timezone_automatic_detection() &&
+      policy.system_timezone_automatic_detection()
+          .has_timezone_detection_type()) {
+    policies->Set(
+        key::kSystemTimezoneAutomaticDetection, POLICY_LEVEL_MANDATORY,
+        POLICY_SCOPE_MACHINE, POLICY_SOURCE_CLOUD,
+        new base::FundamentalValue(policy.system_timezone_automatic_detection()
+                                       .timezone_detection_type()),
+        nullptr);
+  }
 }
 
 }  // namespace