Framework to allow Chromoting host to respect NAT traversal policy in linux.

remoting/host/plugin/policy_hack/nat_policy.h

+// Copyright (c) 2011 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 REMOTING_HOST_PLUGIN_POLICY_HACK_NAT_POLICY_H_
+#define REMOTING_HOST_PLUGIN_POLICY_HACK_NAT_POLICY_H_
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+
+class MessageLoop;
+
+namespace base {
+class WaitableEvent;
+}  // namespace base
+
+namespace remoting {
+namespace policy_hack {
+
+// Watches the policy files for a change to the remote access host NAT

[dmac, 2011/08/11 18:42:55]

this is not actually true for all platforms. How about just "Watches for changes
to the remote access host NAT policies".

[awong, 2011/08/11 19:04:07]

done

+// policies.
+class NatPolicy {
+ public:
+  // Called with the current status of whether or not NAT traversal is enabled.
+  typedef base::Callback<void(bool)> NatEnabledCallback;
+
+  NatPolicy() {}
+  virtual ~NatPolicy() {}
+
+  // This guarantees that the policy_update_cb is called at least once with the
+  // current policy.
+  virtual void StartWatching() = 0;
+
+  virtual void StopWatching(base::WaitableEvent* done) = 0;
+
+  // Implemented by each platform.

[Wez, 2011/08/11 20:00:27]

Document which MessageLoop needs to be passed, and under what circumstances the
callback will be called.
Why pass the callback here, rather than to StartWatching()?

[awong, 2011/08/11 23:54:54]

Done.
No real good reason...moved to StartWatching().

+  static NatPolicy* Create(MessageLoop* message_loop,
+                           const NatEnabledCallback& policy_update_cb);
+};
+
+}  // namespace policy_hack
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_PLUGIN_POLICY_HACK_NAT_POLICY_H_