Use srcset's resource pixel density to determine intrinsic size

Source/core/rendering/RenderImageResource.cpp

Index: Source/core/rendering/RenderImageResource.cpp
diff --git a/Source/core/rendering/RenderImageResource.cpp b/Source/core/rendering/RenderImageResource.cpp
index 61301870230f8eafc483f877c34cafa9eec661b2..ffd1dc3f53bf1797b846b43ea17b286e76d90308 100644
--- a/Source/core/rendering/RenderImageResource.cpp
+++ b/Source/core/rendering/RenderImageResource.cpp
@@ -30,6 +30,7 @@
 
 #include "core/fetch/ImageResource.h"
 #include "core/platform/graphics/Image.h"
+#include "core/rendering/RenderImage.h"
 #include "core/rendering/RenderObject.h"
 
 namespace WebCore {
@@ -103,4 +104,14 @@ Image* RenderImageResource::nullImage()
     return Image::nullImage();
 }
 
+LayoutSize RenderImageResource::getImageSize(float multiplier, ImageResource::SizeType type) const
+{
+    if (!m_cachedImage)
+        return LayoutSize();
+    LayoutSize size = m_cachedImage->imageSizeForRenderer(m_renderer, multiplier, type);
+    if (m_renderer && m_renderer->isRenderImage())
+        size.scale(toRenderImage(m_renderer)->imageDevicePixelRatio());
+    return size;
+}
+
 } // namespace WebCore