diff -r 000000000000 -r 6474c204b198 dom/events/TransitionEvent.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/events/TransitionEvent.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,100 @@
+/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
+/* 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/TransitionEvent.h"
+#include "mozilla/ContentEvents.h"
+#include "prtime.h"
+
+namespace mozilla {
+namespace dom {
+
+TransitionEvent::TransitionEvent(EventTarget* aOwner,
+                                 nsPresContext* aPresContext,
+                                 InternalTransitionEvent* aEvent)
+  : Event(aOwner, aPresContext,
+          aEvent ? aEvent : new InternalTransitionEvent(false, 0))
+{
+  if (aEvent) {
+    mEventIsInternal = false;
+  }
+  else {
+    mEventIsInternal = true;
+    mEvent->time = PR_Now();
+  }
+}
+
+NS_INTERFACE_MAP_BEGIN(TransitionEvent)
+  NS_INTERFACE_MAP_ENTRY(nsIDOMTransitionEvent)
+NS_INTERFACE_MAP_END_INHERITING(Event)
+
+NS_IMPL_ADDREF_INHERITED(TransitionEvent, Event)
+NS_IMPL_RELEASE_INHERITED(TransitionEvent, Event)
+
+// static
+already_AddRefed<TransitionEvent>
+TransitionEvent::Constructor(const GlobalObject& aGlobal,
+                             const nsAString& aType,
+                             const TransitionEventInit& aParam,
+                             ErrorResult& aRv)
+{
+  nsCOMPtr<EventTarget> t = do_QueryInterface(aGlobal.GetAsSupports());
+  nsRefPtr<TransitionEvent> e = new TransitionEvent(t, nullptr, nullptr);
+  bool trusted = e->Init(t);
+
+  aRv = e->InitEvent(aType, aParam.mBubbles, aParam.mCancelable);
+
+  InternalTransitionEvent* internalEvent = e->mEvent->AsTransitionEvent();
+  internalEvent->propertyName = aParam.mPropertyName;
+  internalEvent->elapsedTime = aParam.mElapsedTime;
+  internalEvent->pseudoElement = aParam.mPseudoElement;
+
+  e->SetTrusted(trusted);
+  return e.forget();
+}
+
+NS_IMETHODIMP
+TransitionEvent::GetPropertyName(nsAString& aPropertyName)
+{
+  aPropertyName = mEvent->AsTransitionEvent()->propertyName;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TransitionEvent::GetElapsedTime(float* aElapsedTime)
+{
+  *aElapsedTime = ElapsedTime();
+  return NS_OK;
+}
+
+float
+TransitionEvent::ElapsedTime()
+{
+  return mEvent->AsTransitionEvent()->elapsedTime;
+}
+
+NS_IMETHODIMP
+TransitionEvent::GetPseudoElement(nsAString& aPseudoElement)
+{
+  aPseudoElement = mEvent->AsTransitionEvent()->pseudoElement;
+  return NS_OK;
+}
+
+} // namespace dom
+} // namespace mozilla
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+nsresult
+NS_NewDOMTransitionEvent(nsIDOMEvent** aInstancePtrResult,
+                         EventTarget* aOwner,
+                         nsPresContext* aPresContext,
+                         InternalTransitionEvent* aEvent)
+{
+  TransitionEvent *it = new TransitionEvent(aOwner, aPresContext, aEvent);
+  NS_ADDREF(it);
+  *aInstancePtrResult = static_cast<Event*>(it);
+  return NS_OK;
+}