Reduce unneeded policy fetches by detecting expired invalidations.

components/policy/core/common/cloud/enterprise_metrics.h

 // 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.
 
 #ifndef COMPONENTS_POLICY_CORE_COMMON_CLOUD_ENTERPRISE_METRICS_H_
 #define COMPONENTS_POLICY_CORE_COMMON_CLOUD_ENTERPRISE_METRICS_H_
 
 #include "components/policy/policy_export.h"
 
 namespace policy {
@@ skipping 174 matching lines @@
   // A refresh occurred while the policy was invalidated and the policy was
   // changed.
   METRIC_POLICY_REFRESH_INVALIDATED_CHANGED,
   // A refresh occurred while the policy was invalidated and the policy was
   // unchanged.
   METRIC_POLICY_REFRESH_INVALIDATED_UNCHANGED,
 
   METRIC_POLICY_REFRESH_SIZE  // Must be the last.
 };
 
+// Types of policy invalidations.
+enum PolicyInvalidationType {
+  // The invalidation contained no payload.
+  POLICY_INVALIDATION_TYPE_NO_PAYLOAD,
+  // A normal invalidation containing a payload.
+  POLICY_INVALIDATION_TYPE_NORMAL,
+  // The invalidation contained no payload and was considered expired.
+  POLICY_INVALIDATION_TYPE_NO_PAYLOAD_EXPIRED,
+  // The invalidation contained a payload and was considered expired.
+  POLICY_INVALIDATION_TYPE_EXPIRED,
+
+  POLICY_INVALIDATION_TYPE_SIZE  // Must be the last.
+};
+
 // Names for the UMA counters. They are shared from here since the events
 // from the same enum above can be triggered in different files, and must use
 // the same UMA histogram name.
 POLICY_EXPORT extern const char kMetricToken[];
 POLICY_EXPORT extern const char kMetricPolicy[];
 POLICY_EXPORT extern const char kMetricEnrollment[];
 POLICY_EXPORT extern const char kMetricPolicyRefresh[];
 POLICY_EXPORT extern const char kMetricPolicyInvalidations[];
 
 }  // namespace policy
 
 #endif  // COMPONENTS_POLICY_CORE_COMMON_CLOUD_ENTERPRISE_METRICS_H_