Revert of [ios] Move WebStateList to ios/chrome/browser/web_state_list.

ios/chrome/browser/web_state_list/web_state_list_fast_enumeration_helper.h

Index: ios/chrome/browser/web_state_list/web_state_list_fast_enumeration_helper.h
diff --git a/ios/chrome/browser/web_state_list/web_state_list_fast_enumeration_helper.h b/ios/chrome/browser/web_state_list/web_state_list_fast_enumeration_helper.h
deleted file mode 100644
index 369d53e2000f4628fce0e93307ff13718a487cba..0000000000000000000000000000000000000000
--- a/ios/chrome/browser/web_state_list/web_state_list_fast_enumeration_helper.h
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright 2017 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_WEB_STATE_LIST_WEB_STATE_LIST_FAST_ENUMERATION_HELPER_H_
-#define IOS_CHROME_BROWSER_WEB_STATE_LIST_WEB_STATE_LIST_FAST_ENUMERATION_HELPER_H_
-
-#import <Foundation/Foundation.h>
-
-class WebStateList;
-
-namespace web {
-class WebState;
-}
-
-// Protocol used to get Objective-C proxies for WebStates.
-@protocol WebStateProxyFactory
-
-// Returns an Objective-C object corresponding to a given WebState.
-- (id)proxyForWebState:(web::WebState*)webState;
-
-@end
-
-// Helper class allowing NSFastEnumeration over a WebStateList.
-@interface WebStateListFastEnumerationHelper : NSObject<NSFastEnumeration>
-
-- (instancetype)initWithWebStateList:(WebStateList*)webStateList
-                        proxyFactory:(id<WebStateProxyFactory>)proxyFactory
-    NS_DESIGNATED_INITIALIZER;
-
-- (instancetype)init NS_UNAVAILABLE;
-
-@end
-
-#endif  // IOS_CHROME_BROWSER_WEB_STATE_LIST_WEB_STATE_LIST_FAST_ENUMERATION_HELPER_H_