chromeos: Move files in //ash/common to //ash, part 2

ash/shell_observer.h

 // 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 ASH_COMMON_SHELL_OBSERVER_H_
-#define ASH_COMMON_SHELL_OBSERVER_H_
+#ifndef ASH_SHELL_OBSERVER_H_
+#define ASH_SHELL_OBSERVER_H_
 
 #include "ash/ash_export.h"
-#include "ash/common/login_status.h"
+#include "ash/login_status.h"
 
 namespace ash {
 
 class WmWindow;
 
 class ASH_EXPORT ShellObserver {
  public:
   // Invoked when the user logs in.
   virtual void OnLoginStateChanged(LoginStatus status) {}
 
@@ skipping 52 matching lines @@
 
   // Called at the end of Shell::Init.
   virtual void OnShellInitialized() {}
 
  protected:
   virtual ~ShellObserver() {}
 };
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SHELL_OBSERVER_H_
+#endif  // ASH_SHELL_OBSERVER_H_