Have srcset respond to viewport changes

Source/core/rendering/RenderImage.h

Index: Source/core/rendering/RenderImage.h
diff --git a/Source/core/rendering/RenderImage.h b/Source/core/rendering/RenderImage.h
index 0313703b8c79570a15f86c106a06b17e76d0412d..f45e3fc5a86017878fd840ff891ed9427817a05e 100644
--- a/Source/core/rendering/RenderImage.h
+++ b/Source/core/rendering/RenderImage.h
@@ -64,6 +64,12 @@ public:
     inline void setImageDevicePixelRatio(float factor) { m_imageDevicePixelRatio = factor; }
     float imageDevicePixelRatio() const { return m_imageDevicePixelRatio; }
 
+    virtual void intrinsicSizeChanged() OVERRIDE
+    {
+        if (m_imageResource)
+            imageChanged(m_imageResource->imagePtr());
+    }
+
 protected:
     virtual bool needsPreferredWidthsRecalculation() const OVERRIDE FINAL;
     virtual RenderBox* embeddedContentBox() const OVERRIDE FINAL;
@@ -76,12 +82,6 @@ protected:
     virtual void layout() OVERRIDE;
     virtual bool updateImageLoadingPriorities() OVERRIDE FINAL;
 
-    virtual void intrinsicSizeChanged() OVERRIDE
-    {
-        if (m_imageResource)
-            imageChanged(m_imageResource->imagePtr());
-    }
-
 private:
     virtual const char* renderName() const OVERRIDE { return "RenderImage"; }