Teach SVGImage::containerSize() to deduce intrinsic values

Source/core/svg/graphics/SVGImage.cpp

Index: Source/core/svg/graphics/SVGImage.cpp
diff --git a/Source/core/svg/graphics/SVGImage.cpp b/Source/core/svg/graphics/SVGImage.cpp
index 88cd91b701dece68fed9b64a2e83845ba2bb5218..b9513150f1f21e6751fab7962fa1d2c60e988768 100644
--- a/Source/core/svg/graphics/SVGImage.cpp
+++ b/Source/core/svg/graphics/SVGImage.cpp
@@ -162,16 +162,21 @@ IntSize SVGImage::containerSize() const
     // 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 (intrinsicSize.isEmpty() && intrinsicRatio) {

[pdr., 2014/06/06 03:54:50]

This logic seems correct but why isn't it needed elsewhere such as
RenderReplaced::computeAspectRatioInformationForRenderBox?

computeAspectRatioInformationForRenderBox seems to have some similar logic
through calling computeReplacedLogicalHeight.

[davve, 2014/06/06 20:26:26]

AFAICT, private method computeAspectRatioInformationForRenderBox is a workhorse
for computeReplacedLogicalHeight and computeReplacedLogicalWidth that has
corresponding logic as part of the replaced element layout.

One difference is that computeAspectRatioInformationForRenderBox() returns both
size and ratio, containerSize() only returns size. Not resolving using ratio
loses information.

+        if (!intrinsicSize.width() && intrinsicSize.height())
+            intrinsicSize.setWidth(intrinsicSize.height() * intrinsicRatio);
+        else if (intrinsicSize.width() && !intrinsicSize.height())
+            intrinsicSize.setHeight(intrinsicSize.width() / intrinsicRatio);
+    }
 
-    if (!currentSize.isEmpty())
-        return IntSize(static_cast<int>(ceilf(currentSize.width())), static_cast<int>(ceilf(currentSize.height())));
+    if (!intrinsicSize.isEmpty())
+        return IntSize(static_cast<int>(ceilf(intrinsicSize.width())), static_cast<int>(ceilf(intrinsicSize.height())));

[pdr., 2014/06/06 03:54:50]

I think this is just expandedIntSize

[davve, 2014/06/06 20:26:27]

Done.

 
-    // As last resort, use CSS default intrinsic size.
+    // As last resort, use CSS replaced element fallback size.
     return IntSize(300, 150);
 }