diff -r 000000000000 -r 6474c204b198 dom/events/InternalMutationEvent.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/events/InternalMutationEvent.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,70 @@
+/* -*- 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 mozilla_MutationEvent_h__
+#define mozilla_MutationEvent_h__
+
+#include "mozilla/BasicEvents.h"
+#include "nsCOMPtr.h"
+#include "nsIAtom.h"
+#include "nsIDOMNode.h"
+
+namespace mozilla {
+
+class InternalMutationEvent : public WidgetEvent
+{
+public:
+  virtual InternalMutationEvent* AsMutationEvent() MOZ_OVERRIDE { return this; }
+
+  InternalMutationEvent(bool aIsTrusted, uint32_t aMessage) :
+    WidgetEvent(aIsTrusted, aMessage, NS_MUTATION_EVENT),
+    mAttrChange(0)
+  {
+    mFlags.mCancelable = false;
+  }
+
+  virtual WidgetEvent* Duplicate() const MOZ_OVERRIDE
+  {
+    MOZ_ASSERT(eventStructType == NS_MUTATION_EVENT,
+               "Duplicate() must be overridden by sub class");
+    InternalMutationEvent* result = new InternalMutationEvent(false, message);
+    result->AssignMutationEventData(*this, true);
+    result->mFlags = mFlags;
+    return result;
+  }
+
+  nsCOMPtr<nsIDOMNode> mRelatedNode;
+  nsCOMPtr<nsIAtom>    mAttrName;
+  nsCOMPtr<nsIAtom>    mPrevAttrValue;
+  nsCOMPtr<nsIAtom>    mNewAttrValue;
+  unsigned short       mAttrChange;
+
+  void AssignMutationEventData(const InternalMutationEvent& aEvent,
+                               bool aCopyTargets)
+  {
+    AssignEventData(aEvent, aCopyTargets);
+
+    mRelatedNode = aEvent.mRelatedNode;
+    mAttrName = aEvent.mAttrName;
+    mPrevAttrValue = aEvent.mPrevAttrValue;
+    mNewAttrValue = aEvent.mNewAttrValue;
+    mAttrChange = aEvent.mAttrChange;
+  }
+};
+
+// Bits are actually checked to optimize mutation event firing.
+// That's why I don't number from 0x00.  The first event should
+// always be 0x01.
+#define NS_EVENT_BITS_MUTATION_SUBTREEMODIFIED                0x01
+#define NS_EVENT_BITS_MUTATION_NODEINSERTED                   0x02
+#define NS_EVENT_BITS_MUTATION_NODEREMOVED                    0x04
+#define NS_EVENT_BITS_MUTATION_NODEREMOVEDFROMDOCUMENT        0x08
+#define NS_EVENT_BITS_MUTATION_NODEINSERTEDINTODOCUMENT       0x10
+#define NS_EVENT_BITS_MUTATION_ATTRMODIFIED                   0x20
+#define NS_EVENT_BITS_MUTATION_CHARACTERDATAMODIFIED          0x40
+
+} // namespace mozilla
+
+#endif // mozilla_MutationEvent_h__