Stop explicit inheritance if LayoutStyle doesn't change.

Source/core/layout/style/SVGLayoutStyle.h

 /*
     Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
                   2004, 2005 Rob Buis <buis@kde.org>
     Copyright (C) 2005, 2006 Apple Computer, Inc.
     Copyright (C) Research In Motion Limited 2010. 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
     version 2 of the License, or (at your option) any later version.
@@ skipping 24 matching lines @@
 namespace blink {
 
 class SVGLayoutStyle : public RefCounted<SVGLayoutStyle> {
 public:
     static PassRefPtr<SVGLayoutStyle> create() { return adoptRef(new SVGLayoutStyle); }
     PassRefPtr<SVGLayoutStyle> copy() const { return adoptRef(new SVGLayoutStyle(*this));}
     ~SVGLayoutStyle();
 
     bool inheritedNotEqual(const SVGLayoutStyle*) const;
     void inheritFrom(const SVGLayoutStyle*);
-    void copyNonInheritedFrom(const SVGLayoutStyle*);
+    void copyNonInheritedFromCached(const SVGLayoutStyle*);
 
     StyleDifference diff(const SVGLayoutStyle*) const;
 
     bool operator==(const SVGLayoutStyle&) const;
     bool operator!=(const SVGLayoutStyle& o) const { return !(*this == o); }
 
     // Initial values for all the properties
     static EAlignmentBaseline initialAlignmentBaseline() { return AB_AUTO; }
     static EDominantBaseline initialDominantBaseline() { return DB_AUTO; }
     static EBaselineShift initialBaselineShift() { return BS_BASELINE; }
@@ skipping 392 matching lines @@
         svg_noninherited_flags.f._baselineShift = initialBaselineShift();
         svg_noninherited_flags.f._vectorEffect = initialVectorEffect();
         svg_noninherited_flags.f.bufferedRendering = initialBufferedRendering();
         svg_noninherited_flags.f.maskType = initialMaskType();
     }
 };
 
 } // namespace blink
 
 #endif // SVGLayoutStyle_h