Stop explicit inheritance if LayoutStyle doesn't change.

Source/core/layout/style/SVGLayoutStyle.cpp

 /*
     Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
                   2004, 2005, 2010 Rob Buis <buis@kde.org>
     Copyright (C) Research In Motion Limited 2010. All rights reserved.
 
     Based on khtml code by:
     Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
     Copyright (C) 1999-2003 Lars Knoll (knoll@kde.org)
     Copyright (C) 2002-2003 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Apple Computer, Inc.
@@ skipping 89 matching lines @@
     if (!svgInheritParent)
         return;
 
     fill = svgInheritParent->fill;
     stroke = svgInheritParent->stroke;
     inheritedResources = svgInheritParent->inheritedResources;
 
     svg_inherited_flags = svgInheritParent->svg_inherited_flags;
 }
 
-void SVGLayoutStyle::copyNonInheritedFrom(const SVGLayoutStyle* other)
+void SVGLayoutStyle::copyNonInheritedFromCached(const SVGLayoutStyle* other)
 {
     svg_noninherited_flags = other->svg_noninherited_flags;
     stops = other->stops;
     misc = other->misc;
     resources = other->resources;
 }
 
 StyleDifference SVGLayoutStyle::diff(const SVGLayoutStyle* other) const
 {
     StyleDifference styleDifference;
@@ skipping 105 matching lines @@
 }
 
 EPaintOrderType SVGLayoutStyle::paintOrderType(unsigned index) const
 {
     ASSERT(index < ((1 << kPaintOrderBitwidth)-1));
     unsigned pt = (paintOrder() >> (kPaintOrderBitwidth*index)) & ((1u << kPaintOrderBitwidth) - 1);
     return (EPaintOrderType)pt;
 }
 
 }