Reporting: Implement garbage collector.

net/reporting/reporting_garbage_collector.cc

+// Copyright 2017 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 "net/reporting/reporting_garbage_collector.h"
+
+#include <vector>
+
+#include "base/macros.h"
+#include "base/time/time.h"
+#include "net/reporting/reporting_cache.h"
+#include "net/reporting/reporting_report.h"
+
+namespace net {
+
+// static
+void ReportingGarbageCollector::CollectGarbage(ReportingCache* cache,
+                                               const Policy& policy,
+                                               base::TimeTicks now,
+                                               bool network_changed) {
+  DCHECK(cache);
+
+  if (network_changed && !policy.report_persist_across_network_changes) {
+    cache->RemoveAllReports();
+    return;
+  }
+
+  std::vector<const ReportingReport*> all_reports;
+  cache->GetReports(&all_reports);
+
+  std::vector<const ReportingReport*> reports_to_remove;
+  for (const ReportingReport* report : all_reports) {
+    if (now - report->queued >= policy.report_max_age ||
+        report->attempts >= policy.report_max_attempts) {
+      reports_to_remove.push_back(report);
+    }
+  }
+  cache->RemoveReports(reports_to_remove);
+}
+
+}  // namespace net