Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

chrome/browser/policy/cloud/cloud_policy_invalidator.cc

Index: chrome/browser/policy/cloud/cloud_policy_invalidator.cc
diff --git a/chrome/browser/policy/cloud/cloud_policy_invalidator.cc b/chrome/browser/policy/cloud/cloud_policy_invalidator.cc
index 90ce6edda3e0cf38775548d52f04a2f71da7efa5..061f79a4e9da79e586354c007f2d510e9fd3bf85 100644
--- a/chrome/browser/policy/cloud/cloud_policy_invalidator.cc
+++ b/chrome/browser/policy/cloud/cloud_policy_invalidator.cc
@@ -410,7 +410,8 @@ bool CloudPolicyInvalidator::IsInvalidationExpired(int64_t version) {
   return invalidation_time < last_fetch_time;
 }
 
-int CloudPolicyInvalidator::GetPolicyRefreshMetric(bool policy_changed) {
+MetricPolicyRefresh CloudPolicyInvalidator::GetPolicyRefreshMetric(
+    bool policy_changed) {
   if (policy_changed) {
     if (invalid_)
       return METRIC_POLICY_REFRESH_INVALIDATED_CHANGED;
@@ -423,8 +424,9 @@ int CloudPolicyInvalidator::GetPolicyRefreshMetric(bool policy_changed) {
   return METRIC_POLICY_REFRESH_UNCHANGED;
 }
 
-int CloudPolicyInvalidator::GetInvalidationMetric(bool is_missing_payload,
-                                                  bool is_expired) {
+PolicyInvalidationType CloudPolicyInvalidator::GetInvalidationMetric(
+    bool is_missing_payload,
+    bool is_expired) {
   if (is_expired) {
     if (is_missing_payload)
       return POLICY_INVALIDATION_TYPE_NO_PAYLOAD_EXPIRED;