[ios] Removed alloc_with_zone_interceptor as unused.

ios/web/alloc_with_zone_interceptor.h

Index: ios/web/alloc_with_zone_interceptor.h
diff --git a/ios/web/alloc_with_zone_interceptor.h b/ios/web/alloc_with_zone_interceptor.h
deleted file mode 100644
index 00265405d748091e0c3ec64f9f42109e1502bddf..0000000000000000000000000000000000000000
--- a/ios/web/alloc_with_zone_interceptor.h
+++ /dev/null
@@ -1,18 +0,0 @@
-// 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_WEB_ALLOC_WITH_ZONE_INTERCEPTOR_H_
-#define IOS_WEB_ALLOC_WITH_ZONE_INTERCEPTOR_H_
-
-#import <Foundation/Foundation.h>
-
-namespace web {
-// Adds |impl_block| as a custom implementation for |allocWithZone:| method of
-// |target| Class. AddAllocWithZoneMethod can not swizzle existing
-// |allocWithZone:| method of |target| Class. Neither |target| nor any of its
-// superclases must not have overridden |allocWithZone:|.
-void AddAllocWithZoneMethod(Class target, id (^impl_block)(Class, NSZone*));
-}  // namespace web
-
-#endif  // IOS_WEB_ALLOC_WITH_ZONE_INTERCEPTOR_H_