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

ash/system/virtual_keyboard/virtual_keyboard_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_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_OBSERVER_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_OBSERVER_H_
+#ifndef ASH_SYSTEM_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_OBSERVER_H_
+#define ASH_SYSTEM_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_OBSERVER_H_
 
 #include "ash/ash_export.h"
 
 namespace ash {
 
 class ASH_EXPORT VirtualKeyboardObserver {
  public:
   virtual ~VirtualKeyboardObserver() {}
 
   // Notifies when the keyboard is suppressed.
   virtual void OnKeyboardSuppressionChanged(bool suppressed) = 0;
 };
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_OBSERVER_H_
+#endif  // ASH_SYSTEM_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_OBSERVER_H_