[Oilpan] Prepare full definition of classes before using Member

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

 /*
     Copyright (C) 2010 Rob Buis <rwlbuis@gmail.com>
     Copyright (C) 2011 Cosmin Truta <ctruta@gmail.com>
     Copyright (C) 2012 University of Szeged
     Copyright (C) 2012 Renata Hodovan <reni@webkit.org>
 
     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 24 matching lines @@
 class ResourceFetcher;
 
 class DocumentResource final : public Resource {
 public:
     typedef ResourceClient ClientType;
 
     static ResourcePtr<DocumentResource> fetchSVGDocument(FetchRequest&, ResourceFetcher*);
     ~DocumentResource() override;
     DECLARE_VIRTUAL_TRACE();
 
-    Document* document() const { return m_document.get(); }
+    Document* document() const;
 
     void setEncoding(const String&) override;
     String encoding() const override;
     void checkNotify() override;
 
 private:
     class SVGDocumentResourceFactory : public ResourceFactory {
     public:
         SVGDocumentResourceFactory()
             : ResourceFactory(Resource::SVGDocument) { }
@@ skipping 17 matching lines @@
 class DocumentResourceClient : public ResourceClient {
 public:
     ~DocumentResourceClient() override {}
     static ResourceClientType expectedType() { return DocumentType; }
     ResourceClientType resourceClientType() const override { return expectedType(); }
 };
 
 }
 
 #endif // DocumentResource_h