[SVG2] Elements that don't render shouldn't contribute to ancestor bboxes.

Source/core/rendering/svg/RenderSVGRect.cpp

 /*
  * Copyright (C) 2011 University of Szeged
  * Copyright (C) 2011 Renata Hodovan <reni@webkit.org>
  * 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 111 matching lines @@
     return m_outerStrokeRect.contains(point, FloatRect::InsideOrOnStroke) && !m_innerStrokeRect.contains(point, FloatRect::InsideButNotOnStroke);
 }
 
 bool RenderSVGRect::shapeDependentFillContains(const FloatPoint& point, const WindRule fillRule) const
 {
     if (m_usePathFallback)
         return RenderSVGShape::shapeDependentFillContains(point, fillRule);
     return m_fillBoundingBox.contains(point.x(), point.y());
 }
 
+bool RenderSVGRect::isRenderingDisabled() const
+{
+    // Some combinations of attributes cause SVG elements
+    // to not render.
+    // For rects a negative dimension is an error and
+    // a zero dimension disables rendering.
+    return m_fillBoundingBox.isEmpty();
 }
+
+}