Unify content transformation calculations for SVG clip paths

Source/core/layout/svg/LayoutSVGResourceClipper.h

 /*
  * Copyright (C) Research In Motion Limited 2009-2010. 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 19 matching lines @@
 class LayoutSVGResourceClipper final : public LayoutSVGResourceContainer {
 public:
     explicit LayoutSVGResourceClipper(SVGClipPathElement*);
     virtual ~LayoutSVGResourceClipper();
 
     virtual const char* name() const override { return "LayoutSVGResourceClipper"; }
 
     virtual void removeAllClientsFromCache(bool markForInvalidation = true) override;
     virtual void removeClientFromCache(LayoutObject*, bool markForInvalidation = true) override;
 
+    AffineTransform calculateContentTransformation(const LayoutObject*, const FloatRect& targetBoundingBox);
+
     FloatRect resourceBoundingBox(const LayoutObject*);
 
     static const LayoutSVGResourceType s_resourceType = ClipperResourceType;
     virtual LayoutSVGResourceType resourceType() const override { return s_resourceType; }
 
     bool hitTestClipContent(const FloatRect&, const FloatPoint&);
 
     SVGUnitTypes::SVGUnitType clipPathUnits() const { return toSVGClipPathElement(element())->clipPathUnits()->currentValue()->enumValue(); }
 
-    bool tryPathOnlyClipping(const LayoutObject&, GraphicsContext*, const AffineTransform&, const FloatRect&);
-    PassRefPtr<const SkPicture> createContentPicture(AffineTransform&, const FloatRect&, GraphicsContext*);
+    bool tryPathOnlyClipping(const LayoutObject&, GraphicsContext*, const AffineTransform& contentTransformation);
+    PassRefPtr<const SkPicture> createContentPicture(const AffineTransform& contentTransformation, GraphicsContext*);
 
     bool hasCycle() { return m_inClipExpansion; }
     void beginClipExpansion() { ASSERT(!m_inClipExpansion); m_inClipExpansion = true; }
     void endClipExpansion() { ASSERT(m_inClipExpansion); m_inClipExpansion = false; }
 private:
-    void calculateClipContentPaintInvalidationRect();
+    void calculateClipContentPaintInvalidationRect(const LayoutObject*);
 
     RefPtr<const SkPicture> m_clipContentPicture;
     FloatRect m_clipBoundaries;
 
     // Reference cycle detection.
     bool m_inClipExpansion;
 };
 
 DEFINE_LAYOUT_SVG_RESOURCE_TYPE_CASTS(LayoutSVGResourceClipper, ClipperResourceType);
 
 }
 
 #endif