Teach SVGImage::containerSize() to deduce intrinsic values

Source/core/svg/graphics/SVGImage.cpp

 /*
  * Copyright (C) 2006 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 144 matching lines @@
         return IntSize();
 
     // If a container size is available it has precedence.
     IntSize containerSize = renderer->containerSize();
     if (!containerSize.isEmpty())
         return containerSize;
 
     // Assure that a container size is always given for a non-identity zoom level.
     ASSERT(renderer->style()->effectiveZoom() == 1);
 
-    FloatSize currentSize;
-    if (rootElement->hasIntrinsicWidth() && rootElement->hasIntrinsicHeight())
-        currentSize = rootElement->currentViewportSize();
-    else
-        currentSize = rootElement->currentViewBoxRect().size();
+    FloatSize intrinsicSize;
+    double intrinsicRatio = 0;
+    renderer->computeIntrinsicRatioInformation(intrinsicSize, intrinsicRatio);
 
-    if (!currentSize.isEmpty())
-        return IntSize(static_cast<int>(ceilf(currentSize.width())), static_cast<int>(ceilf(currentSize.height())));
+    if (intrinsicSize.isEmpty() && intrinsicRatio) {
+        if (!intrinsicSize.width() && intrinsicSize.height())
+            intrinsicSize.setWidth(intrinsicSize.height() * intrinsicRatio);
+        else if (intrinsicSize.width() && !intrinsicSize.height())
+            intrinsicSize.setHeight(intrinsicSize.width() / intrinsicRatio);
+    }
 
-    // As last resort, use CSS default intrinsic size.
+    if (!intrinsicSize.isEmpty())
+        return expandedIntSize(intrinsicSize);
+
+    // As last resort, use CSS replaced element fallback size.
     return IntSize(300, 150);
 }
 
 void SVGImage::drawForContainer(GraphicsContext* context, const FloatSize containerSize, float zoom, const FloatRect& dstRect,
     const FloatRect& srcRect, CompositeOperator compositeOp, blink::WebBlendMode blendMode)
 {
     if (!m_page)
         return;
 
     // Temporarily disable the image observer to prevent changeInRect() calls due re-laying out the image.
@@ skipping 232 matching lines @@
 
     return m_page;
 }
 
 String SVGImage::filenameExtension() const
 {
     return "svg";
 }
 
 }