Removed NativeAppsCollectionViewController and related code.

ios/chrome/browser/ui/settings/native_apps_collection_view_controller_private.h

-// Copyright 2015 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 IOS_CHROME_BROWSER_UI_SETTINGS_NATIVE_APPS_COLLECTION_VIEW_CONTROLLER_PRIVATE_H_
-#define IOS_CHROME_BROWSER_UI_SETTINGS_NATIVE_APPS_COLLECTION_VIEW_CONTROLLER_PRIVATE_H_
-
-#import "ios/chrome/browser/ui/settings/native_apps_collection_view_controller.h"
-
-// This file is a private header for NativeAppsCollectionViewController.
-// It exposes private details for testing purposes.
-
-namespace settings {
-
-// User actions.
-typedef enum {
-  kNativeAppsActionDidNothing,
-  kNativeAppsActionClickedInstall,
-  kNativeAppsActionTurnedDefaultBrowserOn,
-  kNativeAppsActionTurnedDefaultBrowserOff,
-  kNativeAppsActionTurnedAutoOpenOn,
-  kNativeAppsActionTurnedAutoOpenOff,
-  kNativeAppsActionCount,
-} NativeAppsAction;
-
-}  // namespace settings
-
-// Arbitrary value to shift indices (from 0 to N), to a range that doesn't
-// include 0, in order to not mistake the default value (0) with the first
-// index. That way, an invalid (or default) tag value can be detected.
-// That means that all app cells have a tag computed by adding their index and
-// this shift.
-extern const NSInteger kTagShift;
-
-#endif  // IOS_CHROME_BROWSER_UI_SETTINGS_NATIVE_APPS_COLLECTION_VIEW_CONTROLLER_PRIVATE_H_