Use {To/From}JavaTime for policy timestamps

components/policy/core/common/cloud/cloud_policy_validator_unittest.cc

Index: components/policy/core/common/cloud/cloud_policy_validator_unittest.cc
diff --git a/components/policy/core/common/cloud/cloud_policy_validator_unittest.cc b/components/policy/core/common/cloud/cloud_policy_validator_unittest.cc
index c61675fc630072c5251c9b056ffa108410a3d28f..cb4548a2d45a897f686a98d7daec1f261d53815d 100644
--- a/components/policy/core/common/cloud/cloud_policy_validator_unittest.cc
+++ b/components/policy/core/common/cloud/cloud_policy_validator_unittest.cc
@@ -43,9 +43,7 @@ ACTION_P(CheckStatus, expected_status) {
 class CloudPolicyValidatorTest : public testing::Test {
  public:
   CloudPolicyValidatorTest()
-      : timestamp_(base::Time::UnixEpoch() +
-                   base::TimeDelta::FromMilliseconds(
-                       PolicyBuilder::kFakeTimestamp)),
+      : timestamp_(base::Time::FromJavaTime(PolicyBuilder::kFakeTimestamp)),
         timestamp_option_(CloudPolicyValidatorBase::TIMESTAMP_FULLY_VALIDATED),
         dm_token_option_(CloudPolicyValidatorBase::DM_TOKEN_REQUIRED),
         device_id_option_(CloudPolicyValidatorBase::DEVICE_ID_REQUIRED),
@@ -207,15 +205,13 @@ TEST_F(CloudPolicyValidatorTest, IgnoreMissingTimestamp) {
 
 TEST_F(CloudPolicyValidatorTest, ErrorOldTimestamp) {
   base::Time timestamp(timestamp_ - base::TimeDelta::FromMinutes(5));
-  policy_.policy_data().set_timestamp(
-      (timestamp - base::Time::UnixEpoch()).InMilliseconds());
+  policy_.policy_data().set_timestamp(timestamp.ToJavaTime());
   Validate(CheckStatus(CloudPolicyValidatorBase::VALIDATION_BAD_TIMESTAMP));
 }
 
 TEST_F(CloudPolicyValidatorTest, ErrorTimestampFromTheFuture) {
   base::Time timestamp(timestamp_ + base::TimeDelta::FromHours(3));
-  policy_.policy_data().set_timestamp(
-      (timestamp - base::Time::UnixEpoch()).InMilliseconds());
+  policy_.policy_data().set_timestamp(timestamp.ToJavaTime());
   Validate(CheckStatus(CloudPolicyValidatorBase::VALIDATION_BAD_TIMESTAMP));
 }
 
@@ -223,8 +219,7 @@ TEST_F(CloudPolicyValidatorTest, IgnoreErrorTimestampFromTheFuture) {
   base::Time timestamp(timestamp_ + base::TimeDelta::FromMinutes(5));
   timestamp_option_ =
       CloudPolicyValidatorBase::TIMESTAMP_NOT_BEFORE;
-  policy_.policy_data().set_timestamp(
-      (timestamp - base::Time::UnixEpoch()).InMilliseconds());
+  policy_.policy_data().set_timestamp(timestamp.ToJavaTime());
   Validate(CheckStatus(CloudPolicyValidatorBase::VALIDATION_OK));
 }