Oilpan: have ResourceFetcher use a prefinalizer.

Source/core/fetch/ResourceFetcher.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, 2009, 2010, 2011 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     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 50 matching lines @@
 // The ResourceFetcher provides a per-context interface to the MemoryCache
 // and enforces a bunch of security checks and rules for resource revalidation.
 // Its lifetime is roughly per-DocumentLoader, in that it is generally created
 // in the DocumentLoader constructor and loses its ability to generate network
 // requests when the DocumentLoader is destroyed. Documents also hold a pointer
 // to ResourceFetcher for their lifetime (and will create one if they
 // are initialized without a LocalFrame), so a Document can keep a ResourceFetcher
 // alive past detach if scripts still reference the Document.
 class CORE_EXPORT ResourceFetcher : public GarbageCollectedFinalized<ResourceFetcher> {
     WTF_MAKE_NONCOPYABLE(ResourceFetcher);
+    WILL_BE_USING_PRE_FINALIZER(ResourceFetcher, clearPreloads);
 public:
     static ResourceFetcher* create(FetchContext* context) { return new ResourceFetcher(context); }
     virtual ~ResourceFetcher();
     DECLARE_VIRTUAL_TRACE();
 
     ResourcePtr<Resource> requestResource(FetchRequest&, const ResourceFactory&);
 
     Resource* cachedResource(const KURL&) const;
 
     typedef HashMap<String, ResourcePtr<Resource>> DocumentResourceMap;
@@ skipping 158 matching lines @@
             m_loader->m_allowStaleResources = m_previousState;
     }
 private:
     Member<ResourceFetcher> m_loader;
     bool m_previousState;
 };
 
 } // namespace blink
 
 #endif // ResourceFetcher_h