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/time/time.h"
+#include "net/reporting/reporting_cache.h"
+
+namespace net {
+
+using Report = ReportingCache::Report;
+
+// static
+void ReportingGarbageCollector::CollectGarbage(ReportingCache* cache,
+                                               const Policy& policy,
+                                               base::TimeTicks now,
+                                               bool network_changed) {

[shivanisha, 2017/03/16 00:22:45]

DCHECK(cache)

[Julia Tuttle, 2017/03/21 19:26:57]

Done.

+  std::vector<const Report*> all_reports;
+  cache->GetReports(&all_reports);
+
+  if (network_changed && !policy.report_persist_across_network_changes) {
+    cache->RemoveReports(all_reports);

[shivanisha, 2017/03/16 00:22:45]

Since this policy is for all the reports, how about having a RemoveAllReports
API as well which can be invoked here and don't need to invoke GetReports before
this call.

[Julia Tuttle, 2017/03/21 19:26:57]

Done.

+    return;
+  }
+
+  std::vector<const Report*> reports_to_remove;
+  for (const Report* 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