Clean up forward declarations in Source/core/fetch and /loader

Source/core/fetch/Resource.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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 22 matching lines @@
 #include "wtf/HashSet.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/text/WTFString.h"
 
 // FIXME(crbug.com/352043): This is temporarily enabled even on RELEASE to diagnose a wild crash.
 #define ENABLE_RESOURCE_IS_DELETED_CHECK
 
 namespace blink {
 
 struct FetchInitiatorInfo;
-class MemoryCache;
 class CachedMetadata;
 class ResourceClient;
 class ResourcePtrBase;
 class ResourceFetcher;
 class InspectorResource;
 class ResourceLoader;
 class SecurityOrigin;
 class SharedBuffer;
 
 // A resource that is held in the cache. Classes who want to use this object should derive
@@ skipping 362 matching lines @@
 const char* ResourceTypeName(Resource::Type);
 #endif
 
 #define DEFINE_RESOURCE_TYPE_CASTS(typeName) \
     DEFINE_TYPE_CASTS(typeName##Resource, Resource, resource, resource->type() == Resource::typeName, resource.type() == Resource::typeName); \
     inline typeName##Resource* to##typeName##Resource(const ResourcePtr<Resource>& ptr) { return to##typeName##Resource(ptr.get()); }
 
 }
 
 #endif