diff --git a/real_system_state.h b/real_system_state.h
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--- /dev/null
+++ b/real_system_state.h
@@ -0,0 +1,99 @@
+// Copyright (c) 2013 The Chromium OS 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 CHROMEOS_PLATFORM_UPDATE_ENGINE_REAL_SYSTEM_STATE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_REAL_SYSTEM_STATE_H_
+
+#include <update_engine/system_state.h>
+
+#include <update_engine/connection_manager.h>
+#include <update_engine/gpio_handler.h>
+#include <update_engine/payload_state.h>
+#include <update_engine/prefs.h>
+#include <update_engine/update_attempter.h>
+
+namespace chromeos_update_engine {
+
+// A real implementation of the SystemStateInterface which is
+// used by the actual product code.
+class RealSystemState : public SystemState {
+public:
+  // Constructors and destructors.
+  RealSystemState();
+  virtual ~RealSystemState() {}
+
+  virtual bool IsOOBEComplete();
+
+  virtual inline void set_device_policy(
+      const policy::DevicePolicy* device_policy) {
+    device_policy_ = device_policy;
+  }
+
+  virtual inline const policy::DevicePolicy* device_policy() const {
+    return device_policy_;
+  }
+
+  virtual inline ConnectionManager* connection_manager() {
+    return &connection_manager_;
+  }
+
+  virtual inline MetricsLibraryInterface* metrics_lib() {
+    return &metrics_lib_;
+  }
+
+  virtual inline PrefsInterface* prefs() {
+    return &prefs_;
+  }
+
+  virtual inline PayloadStateInterface* payload_state() {
+    return &payload_state_;
+  }
+
+  virtual inline GpioHandler* gpio_handler() const {
+    return gpio_handler_.get();
+  }
+
+  virtual inline UpdateAttempter* update_attempter() {
+    return update_attempter_.get();
+  }
+
+  // Initializes this concrete object. Other methods should be invoked only
+  // if the object has been initialized successfully.
+  bool Initialize(bool enable_gpio);
+
+private:
+  // The latest device policy object from the policy provider.
+  const policy::DevicePolicy* device_policy_;
+
+  // The connection manager object that makes download
+  // decisions depending on the current type of connection.
+  ConnectionManager connection_manager_;
+
+  // The Metrics Library interface for reporting UMA stats.
+  MetricsLibrary metrics_lib_;
+
+  // Interface for persisted store.
+  Prefs prefs_;
+
+  // All state pertaining to payload state such as
+  // response, URL, backoff states.
+  PayloadState payload_state_;
+
+  // Pointer to a GPIO handler and other needed modules (note that the order of
+  // declaration significant for destruction, as the latter depends on the
+  // former).
+  scoped_ptr<UdevInterface> udev_iface_;
+  scoped_ptr<FileDescriptor> file_descriptor_;
+  scoped_ptr<GpioHandler> gpio_handler_;
+
+  // The dbus object used to initialize the update attempter.
+  ConcreteDbusGlib dbus_;
+
+  // Pointer to the update attempter object.
+  scoped_ptr<UpdateAttempter> update_attempter_;
+};
+
+}  // namespace chromeos_update_engine
+
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_REAL_SYSTEM_STATE_H_