Align srcset parsing with spec changes

Source/core/html/parser/HTMLSrcsetParser.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 35 matching lines @@
     }
 
     bool foundDescriptor() const
     {
         return (scaleFactor >= 0 || resourceWidth >= 0);
     }
 };
 
 class ImageCandidate {
 public:
+    enum OriginAttribute {
+        SrcsetOrigin,
+        SrcOrigin
+    };
+
     ImageCandidate()
         : m_scaleFactor(1.0)
     {
     }
 
-    ImageCandidate(const String& source, unsigned start, unsigned length, const DescriptorParsingResult& result)
+    ImageCandidate(const String& source, unsigned start, unsigned length, const DescriptorParsingResult& result, OriginAttribute originAttribute)
         : m_string(source.createView(start, length))
         , m_scaleFactor(result.scaleFactor)
         , m_resourceWidth(result.resourceWidth)
+        , m_originAttribute(originAttribute)
     {
     }
 
     String toString() const
     {
         return String(m_string.toString());
     }
 
     AtomicString toAtomicString() const
     {
         return AtomicString(m_string.toString());
     }
 
     void setScaleFactor(float factor)
     {
         m_scaleFactor = factor;
     }
 
     float scaleFactor() const
     {
         return m_scaleFactor;
     }
 
     int resourceWidth() const
     {
         return m_resourceWidth;
     }
 
+    bool srcOrigin() const
+    {
+        return (m_originAttribute == SrcOrigin);
+    }
+
     inline bool isEmpty() const
     {
         return m_string.isEmpty();
     }
 
 private:
     StringView m_string;
     float m_scaleFactor;
     int m_resourceWidth;
+    OriginAttribute m_originAttribute;
 };
 
 ImageCandidate bestFitSourceForSrcsetAttribute(float deviceScaleFactor, int effectiveSize, const String& srcsetAttribute);
 
 ImageCandidate bestFitSourceForImageAttributes(float deviceScaleFactor, int effectiveSize, const String& srcAttribute, const String& srcsetAttribute);
 
 String bestFitSourceForImageAttributes(float deviceScaleFactor, int effectiveSize, const String& srcAttribute, ImageCandidate& srcsetImageCandidate);
 
 }
 
 #endif