Reporting: Implement serializer.

net/reporting/reporting_persister.h

Index: net/reporting/reporting_persister.h
diff --git a/net/reporting/reporting_persister.h b/net/reporting/reporting_persister.h
new file mode 100644
index 0000000000000000000000000000000000000000..6b37a11edc5411418da673f2f74c7f03574d6389
--- /dev/null
+++ b/net/reporting/reporting_persister.h
@@ -0,0 +1,36 @@
+// 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.
+
+#ifndef NET_REPORTING_REPORTING_PERSISTER_H_
+#define NET_REPORTING_REPORTING_PERSISTER_H_
+
+#include <memory>
+
+#include "net/base/net_export.h"
+
+namespace base {
+class Timer;
+}  // namespace base
+
+namespace net {
+
+class ReportingContext;
+
+// Periodically persists the state of the Reporting system to (reasonably)
+// stable storage using the methods provided by the ReportingDelegate.
+class NET_EXPORT ReportingPersister {
+ public:
+  // Creates a ReportingPersister. |context| must outlive the persister.
+  static std::unique_ptr<ReportingPersister> Create(ReportingContext* context);
+
+  virtual ~ReportingPersister();
+
+  // Replaces the internal Timer used for scheduling writes to stable storage
+  // with a caller-specified one so that unittests can provide a MockTimer.
+  virtual void SetTimerForTesting(std::unique_ptr<base::Timer> timer) = 0;
+};
+
+}  // namespace net
+
+#endif  // NET_REPORTING_REPORTING_PERSISTER_H_