diff -r 000000000000 -r 6474c204b198 dom/events/CompositionEvent.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/events/CompositionEvent.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,90 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=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/. */
+
+#include "mozilla/dom/CompositionEvent.h"
+#include "mozilla/TextEvents.h"
+#include "prtime.h"
+
+namespace mozilla {
+namespace dom {
+
+CompositionEvent::CompositionEvent(EventTarget* aOwner,
+                                   nsPresContext* aPresContext,
+                                   WidgetCompositionEvent* aEvent)
+  : UIEvent(aOwner, aPresContext,
+            aEvent ? aEvent : new WidgetCompositionEvent(false, 0, nullptr))
+{
+  NS_ASSERTION(mEvent->eventStructType == NS_COMPOSITION_EVENT,
+               "event type mismatch");
+
+  if (aEvent) {
+    mEventIsInternal = false;
+  } else {
+    mEventIsInternal = true;
+    mEvent->time = PR_Now();
+
+    // XXX compositionstart is cancelable in draft of DOM3 Events.
+    //     However, it doesn't make sence for us, we cannot cancel composition
+    //     when we sends compositionstart event.
+    mEvent->mFlags.mCancelable = false;
+  }
+
+  mData = mEvent->AsCompositionEvent()->data;
+  // TODO: Native event should have locale information.
+}
+
+NS_IMPL_ADDREF_INHERITED(CompositionEvent, UIEvent)
+NS_IMPL_RELEASE_INHERITED(CompositionEvent, UIEvent)
+
+NS_INTERFACE_MAP_BEGIN(CompositionEvent)
+  NS_INTERFACE_MAP_ENTRY(nsIDOMCompositionEvent)
+NS_INTERFACE_MAP_END_INHERITING(UIEvent)
+
+NS_IMETHODIMP
+CompositionEvent::GetData(nsAString& aData)
+{
+  aData = mData;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CompositionEvent::GetLocale(nsAString& aLocale)
+{
+  aLocale = mLocale;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CompositionEvent::InitCompositionEvent(const nsAString& aType,
+                                       bool aCanBubble,
+                                       bool aCancelable,
+                                       nsIDOMWindow* aView,
+                                       const nsAString& aData,
+                                       const nsAString& aLocale)
+{
+  nsresult rv = UIEvent::InitUIEvent(aType, aCanBubble, aCancelable, aView, 0);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mData = aData;
+  mLocale = aLocale;
+  return NS_OK;
+}
+
+} // namespace dom
+} // namespace mozilla
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+nsresult
+NS_NewDOMCompositionEvent(nsIDOMEvent** aInstancePtrResult,
+                          EventTarget* aOwner,
+                          nsPresContext* aPresContext,
+                          WidgetCompositionEvent* aEvent)
+{
+  CompositionEvent* event = new CompositionEvent(aOwner, aPresContext, aEvent);
+  return CallQueryInterface(event, aInstancePtrResult);
+}