chromeos: Move files in //ash/common to //ash, part 1

ash/system/network/network_portal_detector_observer.h

 // Copyright 2014 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 ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_PORTAL_DETECTOR_OBSERVER_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_PORTAL_DETECTOR_OBSERVER_H_
+#ifndef ASH_SYSTEM_NETWORK_NETWORK_PORTAL_DETECTOR_OBSERVER_H_
+#define ASH_SYSTEM_NETWORK_NETWORK_PORTAL_DETECTOR_OBSERVER_H_
 
 #include <string>
 
 namespace ash {
 
 class NetworkPortalDetectorObserver {
  public:
   virtual ~NetworkPortalDetectorObserver() {}
 
   // Called when captive portal is detected for the network associated with
   // |guid|.
   virtual void OnCaptivePortalDetected(const std::string& guid) = 0;
 };
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_PORTAL_DETECTOR_OBSERVER_H_
+#endif  // ASH_SYSTEM_NETWORK_NETWORK_PORTAL_DETECTOR_OBSERVER_H_