[Chromoting] Add a simple Windows app that registers and starts a host.

remoting/host/setup/pin_validator.h

Index: remoting/host/setup/pin_validator.h
diff --git a/remoting/host/setup/pin_validator.h b/remoting/host/setup/pin_validator.h
new file mode 100644
index 0000000000000000000000000000000000000000..51a1e396a0ccb5c54ad4e100d5a400ceeea3b953
--- /dev/null
+++ b/remoting/host/setup/pin_validator.h
@@ -0,0 +1,17 @@
+// Copyright (c) 2012 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_SETUP_PIN_VALIDATOR_H_
+#define REMOTING_HOST_SETUP_PIN_VALIDATOR_H_
+
+#include <string>
+
+namespace remoting {
+
+// Returns whether a PIN is valid.
+bool IsPinValid(const std::string& pin);
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_SETUP_PIN_VALIDATOR_H_