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diff --git a/gfx/src/nsTransform2D.h b/gfx/src/nsTransform2D.h
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+++ b/gfx/src/nsTransform2D.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsTransform2D_h___
+#define nsTransform2D_h___
+
+#include "nsCoord.h"
+
+class nsTransform2D {
+ private:
+  /**
+   * This represents the following matrix (note that the order of row/column
+   * indices is opposite to usual notation)
+   *
+   *      / m00   0   m20  \
+   * M =  |  0   m11  m21  |
+   *      \  0    0    1   /
+   *
+   * Transformation of a coordinate (x, y) is obtained by setting
+   * v = (x, y, 1)^T and evaluating  M . v
+   **/
+
+  float m00, m11, m20, m21;
+
+ public:
+  nsTransform2D(void) {
+    m20 = m21 = 0.0f;
+    m00 = m11 = 1.0f;
+  }
+
+  ~nsTransform2D(void) = default;
+
+  /**
+   * set this transform to a translation
+   *
+   * @param      tx, x translation
+   * @param      ty, y translation
+   **/
+
+  void SetToTranslate(float tx, float ty) {
+    m00 = m11 = 1.0f;
+    m20 = tx;
+    m21 = ty;
+  }
+
+  /**
+   * get the translation portion of this transform
+   *
+   * @param      pt, Point to return translation values in
+   **/
+
+  void GetTranslationCoord(nscoord* ptX, nscoord* ptY) const {
+    *ptX = NSToCoordRound(m20);
+    *ptY = NSToCoordRound(m21);
+  }
+
+  /**
+   * apply matrix to vector
+   *
+   * @param    pt Point to transform
+   **/
+
+  void TransformCoord(nscoord* ptX, nscoord* ptY) const;
+
+  /**
+   * apply matrix to rect
+   *
+   * @param    rect Rect to transform
+   **/
+
+  void TransformCoord(nscoord* aX, nscoord* aY, nscoord* aWidth,
+                      nscoord* aHeight) const;
+
+  /**
+   * add a scale to a Transform via x, y pair
+   *
+   * @param    ptX x value to add as x scale
+   * @param    ptY y value to add as y scale
+   **/
+
+  void AddScale(float ptX, float ptY) {
+    m00 *= ptX;
+    m11 *= ptY;
+  }
+
+  /**
+   * Set the scale (overriding any previous calls to AddScale, but leaving
+   * any existing translation).
+   *
+   * @param    ptX x value to add as x scale
+   * @param    ptY y value to add as y scale
+   **/
+
+  void SetScale(float ptX, float ptY) {
+    m00 = ptX;
+    m11 = ptY;
+  }
+};
+
+#endif