chromeos: Move files in //ash/common to //ash

ash/common/system/chromeos/screen_security/screen_capture_observer.h

-// Copyright 2013 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_SCREEN_SECURITY_SCREEN_CAPTURE_OBSERVER_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_SCREEN_SECURITY_SCREEN_CAPTURE_OBSERVER_H_
-
-#include "base/callback.h"
-#include "base/strings/string16.h"
-
-namespace ash {
-
-class ScreenCaptureObserver {
- public:
-  // Called when screen capture is started.
-  virtual void OnScreenCaptureStart(
-      const base::Closure& stop_callback,
-      const base::string16& screen_capture_status) = 0;
-
-  // Called when screen capture is stopped.
-  virtual void OnScreenCaptureStop() = 0;
-
- protected:
-  virtual ~ScreenCaptureObserver() {}
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_SCREEN_SECURITY_SCREEN_CAPTURE_OBSERVER_H_