Revert "[ios] Ensure proper shutdown of Chrome on iOS."

ios/chrome/browser/ui/main/browser_view_wrangler.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.
 
 #ifndef IOS_CHROME_BROWSER_UI_MAIN_BROWSER_VIEW_WRANGLER_H_
 #define IOS_CHROME_BROWSER_UI_MAIN_BROWSER_VIEW_WRANGLER_H_
 
 #import <UIKit/UIKit.h>
 
 #import "ios/chrome/browser/ui/main/browser_view_information.h"
@@ skipping 39 matching lines @@
 
 // Update the device sharing manager. This should be done after updates to the
 // tab model. This class creates and manages the state of the sharing manager.
 - (void)updateDeviceSharingManager;
 
 // Delete any incognito tab model state, using |removalController| to handle
 // the storage removal.
 - (void)deleteIncognitoTabModelState:
     (BrowsingDataRemovalController*)removalController;
 
-// Called before the instance is deallocated.
-- (void)shutdown;
-
 @end
 
 @interface BrowserViewWrangler (Testing)
 @property(nonatomic, readonly) DeviceSharingManager* deviceSharingManager;
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_MAIN_BROWSER_VIEW_WRANGLER_H_