Remove an unused function from MemoryCache.

third_party/WebKit/Source/core/fetch/MemoryCache.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
@@ skipping 161 matching lines @@
         TypeStatistic xslStyleSheets;
         TypeStatistic fonts;
         TypeStatistic other;
     };
 
     Resource* resourceForURL(const KURL&);
     Resource* resourceForURL(const KURL&, const String& cacheIdentifier);
     WillBeHeapVector<RawPtrWillBeMember<Resource>> resourcesForURL(const KURL&);
 
     void add(Resource*);
-    void replace(Resource* newResource, Resource* oldResource);
     void remove(Resource*);
     bool contains(const Resource*) const;
 
     static KURL removeFragmentIdentifierIfNeeded(const KURL& originalURL);
 
     static String defaultCacheIdentifier();
 
     // Sets the cache's memory capacities, in bytes. These will hold only approximately,
     // since the decoded cost of resources like scripts and stylesheets is not known.
     //  - minDeadBytes: The maximum number of bytes that dead resources should consume when the cache is under pressure.
@@ skipping 136 matching lines @@
 // Returns the global cache.
 CORE_EXPORT MemoryCache* memoryCache();
 
 // Sets the global cache, used to swap in a test instance. Returns the old
 // MemoryCache object.
 CORE_EXPORT MemoryCache* replaceMemoryCacheForTesting(MemoryCache*);
 
 }
 
 #endif