[Proximity Auth] Port the UnlockManager class.

components/proximity_auth/controller.h

+// Copyright 2015 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 COMPONENTS_PROXIMITY_AUTH_CONTROLLER_H
+#define COMPONENTS_PROXIMITY_AUTH_CONTROLLER_H
+
+#include "base/macros.h"
+
+namespace proximity_auth {
+
+class Client;
+
+// Main class that controls the logic flow of the Easy Unlock system.
+class Controller {
+ public:
+  enum class State {
+    NOT_STARTED,
+    FINDING_CONNECTION,
+    AUTHENTICATING,
+    SECURE_CHANNEL_ESTABLISHED,
+    AUTHENTICATION_FAILED,
+    STOPPED,
+  };
+
+  virtual ~Controller() {}
+
+  virtual State GetState() const = 0;
+  virtual Client* GetClient() = 0;
+};
+
+}  // namespace proximity_auth
+
+#endif  // COMPONENTS_PROXIMITY_AUTH_CONTROLLER_H