diff --git a/gfx/src/moz.build b/gfx/src/moz.build
index d8f58a48f1f4..1ea990e64359 100644
--- a/gfx/src/moz.build
+++ b/gfx/src/moz.build
@@ -23,6 +23,7 @@ EXPORTS += [
     'nsColorNameList.h',
     'nsColorNames.h',
     'nsCoord.h',
+    'nsCoordBox.h',
     'nsDeviceContext.h',
     'nsFont.h',
     'nsFontMetrics.h',
diff --git a/gfx/src/nsCoordBox.h b/gfx/src/nsCoordBox.h
new file mode 100644
index 000000000000..d184d70a7314
--- /dev/null
+++ b/gfx/src/nsCoordBox.h
@@ -0,0 +1,24 @@
+/* -*- 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 NSCOORDBOX_H
+#define NSCOORDBOX_H
+
+#include "mozilla/gfx/Box.h"
+#include "nsCoord.h"
+#include "nsRect.h"
+
+// Would like to call this nsBox, but can't because nsBox is a frame type.
+struct nsCoordBox :
+  public mozilla::gfx::BaseBox<nscoord, nsCoordBox, nsRect> {
+  typedef mozilla::gfx::BaseBox<nscoord, nsCoordBox, nsRect> Super;
+
+  nsCoordBox() : Super() {}
+  nsCoordBox(nscoord aX1, nscoord aY1, nscoord aX2, nscoord aY2) :
+      Super(aX1, aY1, aX2, aY2) {}
+};
+
+#endif /* NSCOORDBOX_H */
diff --git a/layout/base/Units.h b/layout/base/Units.h
index 94b4e15d9142..939b4ecf1997 100644
--- a/layout/base/Units.h
+++ b/layout/base/Units.h
@@ -7,6 +7,7 @@
 #ifndef MOZ_UNITS_H_
 #define MOZ_UNITS_H_
 
+#include "mozilla/gfx/Box.h"
 #include "mozilla/gfx/Coord.h"
 #include "mozilla/gfx/Point.h"
 #include "mozilla/gfx/Rect.h"
@@ -74,6 +75,7 @@ typedef gfx::PointTyped<LayerPixel> LayerPoint;
 typedef gfx::IntPointTyped<LayerPixel> LayerIntPoint;
 typedef gfx::SizeTyped<LayerPixel> LayerSize;
 typedef gfx::IntSizeTyped<LayerPixel> LayerIntSize;
+typedef gfx::BoxTyped<LayerPixel> LayerBox;
 typedef gfx::RectTyped<LayerPixel> LayerRect;
 typedef gfx::IntRectTyped<LayerPixel> LayerIntRect;
 typedef gfx::MarginTyped<LayerPixel> LayerMargin;