Use viewBox for SVG image as intrinsic size when all else fails

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 32d839fdebc7156085228a0d38be1ce4a596b7d8..dbb770f8a0e850419f0d6d2b33193c817ba44f11 100644
--- a/Source/core/svg/graphics/SVGImage.cpp
+++ b/Source/core/svg/graphics/SVGImage.cpp
@@ -178,6 +178,13 @@ IntSize SVGImage::containerSize() const
             intrinsicSize.setHeight(intrinsicSize.width() / intrinsicRatio);
     }
 
+    // TODO(davve): In order to maintain aspect ratio the intrinsic
+    // size is faked from the viewBox as a last resort. This may cause
+    // unwanted side effects. Preferably we should be able to signal
+    // the intrinsic ratio in another way.
+    if (intrinsicSize.isEmpty())
+        intrinsicSize = rootElement->currentViewBoxRect().size();
+
     if (!intrinsicSize.isEmpty())
         return expandedIntSize(intrinsicSize);