Alternate approach to updating paint property nodes

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

Index: third_party/WebKit/Source/platform/graphics/paint/TransformPaintPropertyNode.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/TransformPaintPropertyNode.h b/third_party/WebKit/Source/platform/graphics/paint/TransformPaintPropertyNode.h
index 03980087c1c8c198b83549a2574fbd84142fa8b2..775dcc0087de7a842e9e715236a70a426f426741 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/TransformPaintPropertyNode.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/TransformPaintPropertyNode.h
@@ -34,12 +34,17 @@ public:
     TransformPaintPropertyNode* parent() const { return m_parent.get(); }
 
 private:
-
     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;
+    friend class PaintPropertyTreeBuilder;
+    // These setters should only be used by PaintPropertyTreeBuilder.
+    void setMatrix(const TransformationMatrix& matrix) { m_matrix = matrix; }
+    void setOrigin(const FloatPoint3D& origin) { m_origin = origin; }
+    void setParent(PassRefPtr<TransformPaintPropertyNode> parent) { m_parent = parent; }
+
+    TransformationMatrix m_matrix;
+    FloatPoint3D m_origin;
     RefPtr<TransformPaintPropertyNode> m_parent;
 };