SVG does not respect overflow:visible.

Source/core/rendering/svg/RenderSVGRoot.cpp

 /*
  * Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2007, 2008, 2009 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 238 matching lines @@
     if (!firstChild()) {
         SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(this);
         if (!resources || !resources->filter())
             return;
     }
 
     // Make a copy of the PaintInfo because applyTransform will modify the damage rect.
     PaintInfo childPaintInfo(paintInfo);
     childPaintInfo.context->save();
 
-    // Apply initial viewport clip - not affected by overflow handling
-    childPaintInfo.context->clip(pixelSnappedIntRect(overflowClipRect(paintOffset)));
+    // Apply initial viewport clip, the outermost svg is clipped if auto
+    if (style()->overflowX() == OHIDDEN || style()->overflowX() == OAUTO)
+        childPaintInfo.context->clip(pixelSnappedIntRect(overflowClipRect(paintOffset)));
 
     // Convert from container offsets (html renderers) to a relative transform (svg renderers).
     // Transform from our paint container's coordinate system to our local coords.
     IntPoint adjustedPaintOffset = roundedIntPoint(paintOffset);
     childPaintInfo.applyTransform(AffineTransform::translation(adjustedPaintOffset.x(), adjustedPaintOffset.y()) * localToBorderBoxTransform());
 
     // SVGRenderingContext must be destroyed before we restore the childPaintInfo.context, because a filter may have
     // changed the context and it is only reverted when the SVGRenderingContext destructor finishes applying the filter.
     {
         SVGRenderingContext renderingContext;
@@ skipping 170 matching lines @@
 
 bool RenderSVGRoot::hasRelativeLogicalHeight() const
 {
     SVGSVGElement* svg = toSVGSVGElement(node());
     ASSERT(svg);
 
     return svg->intrinsicHeight(SVGSVGElement::IgnoreCSSProperties).isPercent();
 }
 
 }