[Clean Skeleton] Migrate code to clean/

ios/chrome/app/application_step.h

-// Copyright 2016 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.
-
-// ======                        New Architecture                         =====
-// =         This code is only used in the new iOS Chrome architecture.       =
-// ============================================================================
-
-#ifndef IOS_CHROME_APP_APPLICATION_STEP_H_
-#define IOS_CHROME_APP_APPLICATION_STEP_H_
-
-#import <Foundation/Foundation.h>
-
-@class ApplicationState;
-
-// Objects that perform application state change steps must conform to this
-// protocol.
-@protocol ApplicationStep<NSObject>
-// Implementors should not modify |state| in -canRunInState.
-- (BOOL)canRunInState:(ApplicationState*)state;
-
-// Implementors should expect to be deallocated after -runInState is called.
-// If an implementor creates objects that need to persist longer than that, they
-// should be stored in |state.state|.
-// Implementors can assume that they are not in any of |state|'s step arrays
-// when this method is called.
-- (void)runInState:(ApplicationState*)state;
-@end
-
-#endif  // IOS_CHROME_APP_APPLICATION_STEP_H_