Certificate Transparency: New component for obtaining fresh STHs.

net/cert/sth_distributor.h

+// Copyright 2016 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_CERT_STH_DISTRIBUTOR_H_
+#define NET_CERT_STH_DISTRIBUTOR_H_
+
+#include "base/observer_list.h"
+#include "net/base/net_export.h"
+#include "net/cert/sth_observer.h"
+
+namespace net {
+
+namespace ct {
+
+// A proxy for delegating new STH notifications to all registered
+// observers.
+// For each |observer| registered with RegisterObserver, the
+// NewSTHObserved method will be called whenever the STHDistributor's
+// NewSTHObserved method is invoked.
+class NET_EXPORT STHDistributor : public STHObserver, public STHReporter {
+ public:
+  STHDistributor();
+  ~STHDistributor() override;
+
+  // STHObserver implementation.
+  void NewSTHObserved(const SignedTreeHead& sth) override;
+
+  // STHReporter implementation
+  void RegisterObserver(STHObserver* observer) override;
+  void UnregisterObserver(STHObserver* observer) override;
+
+ private:
+  base::ObserverList<STHObserver> observer_list_;
+};
+
+}  // namespace ct
+
+}  // namespace net
+
+#endif  // NET_CERT_STH_DISTRIBUTOR_H_