Use SizesAttributeParser to get the right srcset resource

Source/core/html/HTMLImageElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 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 33 matching lines @@
 namespace WebCore {
 
 using namespace HTMLNames;
 
 HTMLImageElement::HTMLImageElement(Document& document, HTMLFormElement* form)
     : HTMLElement(imgTag, document)
     , m_imageLoader(this)
     , m_compositeOperator(CompositeSourceOver)
     , m_imageDevicePixelRatio(1.0f)
     , m_formWasSetByParser(false)
-    , m_effectiveSize(0)
 {
     ScriptWrappable::init(this);
     if (form && form->inDocument()) {
         m_form = form->createWeakPtr();
         m_formWasSetByParser = true;
         m_form->associate(*this);
         m_form->didAssociateByParser();
     }
 }
 
@@ skipping 84 matching lines @@
     } else {
         m_form = WeakPtr<HTMLFormElement>();
     }
 }
 
 void HTMLImageElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
 {
     if (name == altAttr) {
         if (renderer() && renderer()->isImage())
             toRenderImage(renderer())->updateAltText();
-    } else if (name == srcAttr || name == srcsetAttr) {
-        int effectiveSize = -1; // FIXME - hook up the real value from `sizes`
+    } else if (name == srcAttr || name == srcsetAttr || name == sizesAttr) {
+        int effectiveSize = 0;
+        if (RuntimeEnabledFeatures::pictureSizesEnabled())
+            effectiveSize = SizesAttributeParser::findEffectiveSize(fastGetAttribute(sizesAttr), MediaValuesCached::create(document()));
         ImageCandidate candidate = bestFitSourceForImageAttributes(document().devicePixelRatio(), effectiveSize, fastGetAttribute(srcAttr), fastGetAttribute(srcsetAttr));
         m_bestFitImageURL = candidate.toAtomicString();
         float candidateScaleFactor = candidate.scaleFactor();
+        // FIXME: Make this ">0" part match the spec, once it settles.
         if (candidateScaleFactor > 0)
             m_imageDevicePixelRatio = 1 / candidateScaleFactor;
         if (renderer() && renderer()->isImage())
             toRenderImage(renderer())->setImageDevicePixelRatio(m_imageDevicePixelRatio);
         m_imageLoader.updateFromElementIgnoringPreviousError();
-    } else if (RuntimeEnabledFeatures::pictureSizesEnabled() && name == sizesAttr) {
-        m_effectiveSize = SizesAttributeParser::findEffectiveSize(value, MediaValuesCached::create(document()));
     } else if (name == usemapAttr) {
         setIsLink(!value.isNull());
     } else if (name == compositeAttr) {
         // FIXME: images don't support blend modes in their compositing attribute.
         blink::WebBlendMode blendOp = blink::WebBlendModeNormal;
         if (!parseCompositeAndBlendOperator(value, m_compositeOperator, blendOp))
             m_compositeOperator = CompositeSourceOver;
     } else {
         HTMLElement::parseAttribute(name, value);
     }
@@ skipping 125 matching lines @@
 }
 
 int HTMLImageElement::naturalHeight() const
 {
     if (!m_imageLoader.image())
         return 0;
 
     return m_imageLoader.image()->imageSizeForRenderer(renderer(), 1.0f).height();
 }
 
+const AtomicString& HTMLImageElement::currentSrc() const
+{
+    return m_bestFitImageURL;
+}
+
 bool HTMLImageElement::isURLAttribute(const Attribute& attribute) const
 {
     return attribute.name() == srcAttr
         || attribute.name() == lowsrcAttr
         || attribute.name() == longdescAttr
         || (attribute.name() == usemapAttr && attribute.value().string()[0] != '#')
         || HTMLElement::isURLAttribute(attribute);
 }
 
 bool HTMLImageElement::hasLegalLinkAttribute(const QualifiedName& name) const
@@ skipping 144 matching lines @@
     if (!image)
         return FloatSize();
     LayoutSize size;
     size = image->imageSizeForRenderer(renderer(), 1.0f); // FIXME: Not sure about this.
     if (renderer() && renderer()->isRenderImage() && image->image() && !image->image()->hasRelativeWidth())
         size.scale(toRenderImage(renderer())->imageDevicePixelRatio());
     return size;
 }
 
 }