diff -r 000000000000 -r 6474c204b198 gfx/src/nsScriptableRegion.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/src/nsScriptableRegion.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,161 @@
+/* -*- 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/. */
+
+#include "nsScriptableRegion.h"
+#include <stdint.h>                     // for uint32_t
+#include <sys/types.h>                  // for int32_t
+#include "js/RootingAPI.h"              // for Rooted
+#include "js/Value.h"                   // for INT_TO_JSVAL, etc
+#include "jsapi.h"                      // for JS_DefineElement, etc
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "nsError.h"                    // for NS_OK, NS_ERROR_FAILURE, etc
+#include "nsID.h"
+#include "nsRect.h"                     // for nsIntRect
+#include "nscore.h"                     // for NS_IMETHODIMP
+
+class JSObject;
+struct JSContext;
+
+nsScriptableRegion::nsScriptableRegion()
+{
+}
+
+NS_IMPL_ISUPPORTS(nsScriptableRegion, nsIScriptableRegion)
+
+NS_IMETHODIMP nsScriptableRegion::Init()
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SetToRegion(nsIScriptableRegion *aRegion)
+{
+  aRegion->GetRegion(&mRegion);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SetToRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion = nsIntRect(aX, aY, aWidth, aHeight);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IntersectRegion(nsIScriptableRegion *aRegion)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  mRegion.And(mRegion, region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IntersectRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion.And(mRegion, nsIntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::UnionRegion(nsIScriptableRegion *aRegion)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  mRegion.Or(mRegion, region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::UnionRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion.Or(mRegion, nsIntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SubtractRegion(nsIScriptableRegion *aRegion)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  mRegion.Sub(mRegion, region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SubtractRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion.Sub(mRegion, nsIntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IsEmpty(bool *isEmpty)
+{
+  *isEmpty = mRegion.IsEmpty();
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IsEqualRegion(nsIScriptableRegion *aRegion, bool *isEqual)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  *isEqual = mRegion.IsEqual(region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::GetBoundingBox(int32_t *aX, int32_t *aY, int32_t *aWidth, int32_t *aHeight)
+{
+  nsIntRect boundRect = mRegion.GetBounds();
+  *aX = boundRect.x;
+  *aY = boundRect.y;
+  *aWidth = boundRect.width;
+  *aHeight = boundRect.height;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::Offset(int32_t aXOffset, int32_t aYOffset)
+{
+  mRegion.MoveBy(aXOffset, aYOffset);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::ContainsRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight, bool *containsRect)
+{
+  *containsRect = mRegion.Contains(nsIntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP nsScriptableRegion::GetRegion(nsIntRegion* outRgn)
+{
+  *outRgn = mRegion;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::GetRects(JSContext* aCx, JS::MutableHandle<JS::Value> aRects)
+{
+  uint32_t numRects = mRegion.GetNumRects();
+
+  if (!numRects) {
+    aRects.setNull();
+    return NS_OK;
+  }
+
+  JS::Rooted<JSObject*> destArray(aCx, JS_NewArrayObject(aCx, numRects * 4));
+  if (!destArray) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  aRects.setObject(*destArray);
+
+  uint32_t n = 0;
+  nsIntRegionRectIterator iter(mRegion);
+  const nsIntRect *rect;
+
+  while ((rect = iter.Next())) {
+    if (!JS_DefineElement(aCx, destArray, n, INT_TO_JSVAL(rect->x), nullptr, nullptr, JSPROP_ENUMERATE) ||
+        !JS_DefineElement(aCx, destArray, n + 1, INT_TO_JSVAL(rect->y), nullptr, nullptr, JSPROP_ENUMERATE) ||
+        !JS_DefineElement(aCx, destArray, n + 2, INT_TO_JSVAL(rect->width), nullptr, nullptr, JSPROP_ENUMERATE) ||
+        !JS_DefineElement(aCx, destArray, n + 3, INT_TO_JSVAL(rect->height), nullptr, nullptr, JSPROP_ENUMERATE)) {
+      return NS_ERROR_FAILURE;
+    }
+    n += 4;
+  }
+
+  return NS_OK;
+}