Use SizesAttributeParser to get the right srcset resource

Source/core/html/HTMLImageElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google 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 29 matching lines @@
     static PassRefPtr<HTMLImageElement> create(Document&, HTMLFormElement*);
     static PassRefPtr<HTMLImageElement> createForJSConstructor(Document&, int width, int height);
 
     virtual ~HTMLImageElement();
 
     int width(bool ignorePendingStylesheets = false);
     int height(bool ignorePendingStylesheets = false);
 
     int naturalWidth() const;
     int naturalHeight() const;
+    const AtomicString& currentSrc() const;
 
     bool isServerMap() const;
 
     const AtomicString& altText() const;
 
     CompositeOperator compositeOperator() const { return m_compositeOperator; }
 
     ImageResource* cachedImage() const { return m_imageLoader.image(); }
     void setImageResource(ImageResource* i) { m_imageLoader.setImage(i); };
 
@@ skipping 63 matching lines @@
 
     void resetFormOwner();
 
     HTMLImageLoader m_imageLoader;
     // m_form should be a strong reference in Oilpan.
     WeakPtr<HTMLFormElement> m_form;
     CompositeOperator m_compositeOperator;
     AtomicString m_bestFitImageURL;
     float m_imageDevicePixelRatio;
     bool m_formWasSetByParser;
-    int m_effectiveSize;
 };
 
 } //namespace
 
 #endif