diff -r 000000000000 -r 6474c204b198 dom/smil/nsSMILNullType.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/smil/nsSMILNullType.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,55 @@
+/* -*- 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 "nsSMILNullType.h"
+#include "nsSMILValue.h"
+#include "nsDebug.h"
+
+nsresult
+nsSMILNullType::Assign(nsSMILValue& aDest, const nsSMILValue& aSrc) const
+{
+  NS_PRECONDITION(aDest.mType == aSrc.mType, "Incompatible SMIL types");
+  NS_PRECONDITION(aSrc.mType == this, "Unexpected source type");
+  aDest.mU    = aSrc.mU;
+  aDest.mType = Singleton();
+  return NS_OK;
+}
+
+bool
+nsSMILNullType::IsEqual(const nsSMILValue& aLeft,
+                        const nsSMILValue& aRight) const
+{
+  NS_PRECONDITION(aLeft.mType == aRight.mType, "Incompatible SMIL types");
+  NS_PRECONDITION(aLeft.mType == this, "Unexpected type for SMIL value");
+
+  return true;  // All null-typed values are equivalent.
+}
+
+nsresult
+nsSMILNullType::Add(nsSMILValue& aDest, const nsSMILValue& aValueToAdd,
+                    uint32_t aCount) const
+{
+  NS_NOTREACHED("Adding NULL type");
+  return NS_ERROR_FAILURE;
+}
+
+nsresult
+nsSMILNullType::ComputeDistance(const nsSMILValue& aFrom,
+                                const nsSMILValue& aTo,
+                                double& aDistance) const
+{
+  NS_NOTREACHED("Computing distance for NULL type");
+  return NS_ERROR_FAILURE;
+}
+
+nsresult
+nsSMILNullType::Interpolate(const nsSMILValue& aStartVal,
+                            const nsSMILValue& aEndVal,
+                            double aUnitDistance,
+                            nsSMILValue& aResult) const
+{
+  NS_NOTREACHED("Interpolating NULL type");
+  return NS_ERROR_FAILURE;
+}