Reuse existing paint property node is possible

third_party/WebKit/Source/platform/graphics/paint/TransformPaintPropertyNode.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef TransformPaintPropertyNode_h
 #define TransformPaintPropertyNode_h
 
 #include "platform/PlatformExport.h"
 #include "platform/geometry/FloatPoint3D.h"
 #include "platform/transforms/TransformationMatrix.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 
 #include <iosfwd>
 
 namespace blink {
 
 // A transform created by a css property such as "transform" or "perspective"
 // along with a reference to the parent TransformPaintPropertyNode, or nullptr
 // for the root.
 class PLATFORM_EXPORT TransformPaintPropertyNode : public RefCounted<TransformPaintPropertyNode> {
 public:
-    static PassRefPtr<TransformPaintPropertyNode> create(const TransformationMatrix& matrix, const FloatPoint3D& origin, PassRefPtr<TransformPaintPropertyNode> parent = nullptr)
+    static PassRefPtr<TransformPaintPropertyNode> create(PassRefPtr<TransformPaintPropertyNode> parent, const TransformationMatrix& matrix, const FloatPoint3D& origin)
     {
-        return adoptRef(new TransformPaintPropertyNode(matrix, origin, parent));
+        return adoptRef(new TransformPaintPropertyNode(parent, matrix, origin));
+    }
+
+    void update(PassRefPtr<TransformPaintPropertyNode> parent, const TransformationMatrix& matrix, const FloatPoint3D& origin)
+    {
+        m_parent = parent;
+        m_matrix = matrix;
+        m_origin = origin;
     }
 
     const TransformationMatrix& matrix() const { return m_matrix; }
     const FloatPoint3D& origin() const { return m_origin; }
 
     // Parent transform that this transform is relative to, or nullptr if this
     // is the root transform.
     TransformPaintPropertyNode* parent() const { return m_parent.get(); }
 
 private:
+    TransformPaintPropertyNode(PassRefPtr<TransformPaintPropertyNode> parent, const TransformationMatrix& matrix, const FloatPoint3D& origin)
+        : m_parent(parent), m_matrix(matrix), m_origin(origin) { }
 
-    TransformPaintPropertyNode(const TransformationMatrix& matrix, const FloatPoint3D& origin, PassRefPtr<TransformPaintPropertyNode> parent)
-        : m_matrix(matrix), m_origin(origin), m_parent(parent) { }
-
-    const TransformationMatrix m_matrix;
-    const FloatPoint3D m_origin;
     RefPtr<TransformPaintPropertyNode> m_parent;
+    TransformationMatrix m_matrix;
+    FloatPoint3D m_origin;
 };
 
 // Redeclared here to avoid ODR issues.
 // See platform/testing/PaintPrinters.h.
 void PrintTo(const TransformPaintPropertyNode&, std::ostream*);
 
 } // namespace blink
 
 #endif // TransformPaintPropertyNode_h