SVG does not respect overflow:visible.

Source/core/rendering/svg/SVGRenderSupport.cpp

Index: Source/core/rendering/svg/SVGRenderSupport.cpp
diff --git a/Source/core/rendering/svg/SVGRenderSupport.cpp b/Source/core/rendering/svg/SVGRenderSupport.cpp
index 461735d67531ac691fe71a2580dfd8625553a1b2..cc30bc20fa5614f042e647e5e68a9d193e902e04 100644
--- a/Source/core/rendering/svg/SVGRenderSupport.cpp
+++ b/Source/core/rendering/svg/SVGRenderSupport.cpp
@@ -277,16 +277,10 @@ void SVGRenderSupport::layoutResourcesIfNeeded(const RenderObject* object)
 
 bool SVGRenderSupport::isOverflowHidden(const RenderObject* object)
 {
-    // SVG doesn't support independent x/y overflow
-    ASSERT(object->style()->overflowX() == object->style()->overflowY());
-
-    // OSCROLL is never set for SVG - see StyleResolver::adjustRenderStyle
-    ASSERT(object->style()->overflowX() != OSCROLL);
-
     // RenderSVGRoot should never query for overflow state - it should always clip itself to the initial viewport size.
     ASSERT(!object->isDocumentElement());
 
-    return object->style()->overflowX() == OHIDDEN;
+    return object->style()->overflowX() == OHIDDEN || object->style()->overflowX() == OSCROLL;
 }
 
 void SVGRenderSupport::intersectRepaintRectWithResources(const RenderObject* renderer, FloatRect& repaintRect)