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

ash/system/session/tray_session_length_limit.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_SESSION_TRAY_SESSION_LENGTH_LIMIT_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_SESSION_TRAY_SESSION_LENGTH_LIMIT_H_
+#ifndef ASH_SYSTEM_SESSION_TRAY_SESSION_LENGTH_LIMIT_H_
+#define ASH_SYSTEM_SESSION_TRAY_SESSION_LENGTH_LIMIT_H_
 
 #include <memory>
 
-#include "ash/common/system/chromeos/session/session_length_limit_observer.h"
-#include "ash/common/system/tray/system_tray_item.h"
+#include "ash/system/session/session_length_limit_observer.h"
+#include "ash/system/tray/system_tray_item.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 
 namespace ash {
 namespace test {
 class TraySessionLengthLimitTest;
 }
 
@@ skipping 43 matching lines @@
   LimitState last_limit_state_;  // State of last notification update.
 
   LabelTrayView* tray_bubble_view_;
   std::unique_ptr<base::RepeatingTimer> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(TraySessionLengthLimit);
 };
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_SESSION_TRAY_SESSION_LENGTH_LIMIT_H_
+#endif  // ASH_SYSTEM_SESSION_TRAY_SESSION_LENGTH_LIMIT_H_