Use {To/From}JavaTime for policy timestamps

components/policy/core/common/cloud/cloud_policy_validator.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 "components/policy/core/common/cloud/cloud_policy_validator.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind_helpers.h"
@@ skipping 35 matching lines @@
 };
 
 }  // namespace
 
 CloudPolicyValidatorBase::~CloudPolicyValidatorBase() {}
 
 void CloudPolicyValidatorBase::ValidateTimestamp(
     base::Time not_before,
     ValidateTimestampOption timestamp_option) {
   validation_flags_ |= VALIDATE_TIMESTAMP;
-  timestamp_not_before_ =
-      (not_before - base::Time::UnixEpoch()).InMilliseconds();
+  timestamp_not_before_ = not_before.ToJavaTime();
   timestamp_option_ = timestamp_option;
 }
 
 void CloudPolicyValidatorBase::ValidateUsername(
     const std::string& expected_user,
     bool canonicalize) {
   validation_flags_ |= VALIDATE_USERNAME;
   user_ = expected_user;
   canonicalize_user_ = canonicalize;
 }
@@ skipping 71 matching lines @@
 
 void CloudPolicyValidatorBase::ValidateAgainstCurrentPolicy(
     const em::PolicyData* policy_data,
     ValidateTimestampOption timestamp_option,
     ValidateDMTokenOption dm_token_option,
     ValidateDeviceIdOption device_id_option) {
   base::Time last_policy_timestamp;
   std::string expected_dm_token;
   std::string expected_device_id;
   if (policy_data) {
-    last_policy_timestamp =
-        base::Time::UnixEpoch() +
-        base::TimeDelta::FromMilliseconds(policy_data->timestamp());
+    last_policy_timestamp = base::Time::FromJavaTime(policy_data->timestamp());
     expected_dm_token = policy_data->request_token();
     expected_device_id = policy_data->device_id();
   }
   ValidateTimestamp(last_policy_timestamp, timestamp_option);
   ValidateDMToken(expected_dm_token, dm_token_option);
   ValidateDeviceId(expected_device_id, device_id_option);
 }
 
 CloudPolicyValidatorBase::CloudPolicyValidatorBase(
     std::unique_ptr<em::PolicyFetchResponse> policy_response,
@@ skipping 377 matching lines @@
   return verifier.VerifyFinal();
 }
 
 template class CloudPolicyValidator<em::CloudPolicySettings>;
 
 #if !defined(OS_ANDROID) && !defined(OS_IOS)
 template class CloudPolicyValidator<em::ExternalPolicyData>;
 #endif
 
 }  // namespace policy