diff -r 000000000000 -r 6474c204b198 gfx/src/nsPoint.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/src/nsPoint.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,82 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 NSPOINT_H
+#define NSPOINT_H
+
+#include "nsCoord.h"
+#include "mozilla/gfx/BaseSize.h"
+#include "mozilla/gfx/BasePoint.h"
+#include "nsSize.h"
+
+struct nsIntPoint;
+
+// nsPoint represents a point in app units.
+
+struct nsPoint : public mozilla::gfx::BasePoint<nscoord, nsPoint> {
+  typedef mozilla::gfx::BasePoint<nscoord, nsPoint> Super;
+
+  nsPoint() : Super() {}
+  nsPoint(const nsPoint& aPoint) : Super(aPoint) {}
+  nsPoint(nscoord aX, nscoord aY) : Super(aX, aY) {}
+
+  inline nsIntPoint ScaleToNearestPixels(float aXScale, float aYScale,
+                                         nscoord aAppUnitsPerPixel) const;
+  inline nsIntPoint ToNearestPixels(nscoord aAppUnitsPerPixel) const;
+
+  // Converts this point from aFromAPP, an appunits per pixel ratio, to aToAPP.
+  inline nsPoint ConvertAppUnits(int32_t aFromAPP, int32_t aToAPP) const;
+};
+
+// nsIntPoint represents a point in one of the types of pixels.
+// Uses of nsIntPoint should eventually be converted to CSSIntPoint,
+// LayoutDeviceIntPoint, etc. (see layout/base/Units.h).
+
+struct nsIntPoint : public mozilla::gfx::BasePoint<int32_t, nsIntPoint> {
+  typedef mozilla::gfx::BasePoint<int32_t, nsIntPoint> Super;
+
+  nsIntPoint() : Super() {}
+  nsIntPoint(const nsIntPoint& aPoint) : Super(aPoint) {}
+  nsIntPoint(int32_t aX, int32_t aY) : Super(aX, aY) {}
+
+  inline nsPoint ToAppUnits(nscoord aAppUnitsPerPixel) const;
+};
+
+inline nsIntPoint
+nsPoint::ScaleToNearestPixels(float aXScale, float aYScale,
+                              nscoord aAppUnitsPerPixel) const
+{
+  return nsIntPoint(
+      NSToIntRoundUp(NSAppUnitsToDoublePixels(x, aAppUnitsPerPixel) * aXScale),
+      NSToIntRoundUp(NSAppUnitsToDoublePixels(y, aAppUnitsPerPixel) * aYScale));
+}
+
+inline nsIntPoint
+nsPoint::ToNearestPixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToNearestPixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline nsPoint
+nsPoint::ConvertAppUnits(int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP != aToAPP) {
+    nsPoint point;
+    point.x = NSToCoordRound(NSCoordScale(x, aFromAPP, aToAPP));
+    point.y = NSToCoordRound(NSCoordScale(y, aFromAPP, aToAPP));
+    return point;
+  }
+  return *this;
+}
+
+// app units are integer multiples of pixels, so no rounding needed
+inline nsPoint
+nsIntPoint::ToAppUnits(nscoord aAppUnitsPerPixel) const
+{
+  return nsPoint(NSIntPixelsToAppUnits(x, aAppUnitsPerPixel),
+                 NSIntPixelsToAppUnits(y, aAppUnitsPerPixel));
+}
+
+#endif /* NSPOINT_H */