Make multipart image documents work again.

Source/core/html/ImageDocument.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 44 matching lines @@
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit ImageDocument(const DocumentInit&);
 
     virtual PassRefPtrWillBeRawPtr<DocumentParser> createParser() override;
 #if !ENABLE(OILPAN)
     virtual void dispose() override;
 #endif
 
-    void createDocumentStructure();
+    void createDocumentStructure(bool loadingMultipartContent);
 
     // These methods are for m_shrinkToFitMode == Desktop.
     void resizeImageToFit(ScaleType);
     void restoreImageSize(ScaleType);
     bool imageFitsInWindow() const;
     bool shouldShrinkToFit() const;
     float scale() const;
 
     RefPtrWillBeMember<HTMLImageElement> m_imageElement;
 
@@ skipping 11 matching lines @@
         Desktop
     };
     ShrinkToFitMode m_shrinkToFitMode;
 };
 
 DEFINE_DOCUMENT_TYPE_CASTS(ImageDocument);
 
 }
 
 #endif // ImageDocument_h