diff -r 000000000000 -r 6474c204b198 dom/time/TimeService.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/time/TimeService.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,38 @@
+/* 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 "base/basictypes.h"
+#include "jsapi.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/Hal.h"
+#include "TimeService.h"
+
+namespace mozilla {
+namespace dom {
+namespace time {
+
+NS_IMPL_ISUPPORTS(TimeService, nsITimeService)
+
+/* static */ StaticRefPtr<TimeService> TimeService::sSingleton;
+
+/* static */ already_AddRefed<TimeService>
+TimeService::GetInstance()
+{
+  if (!sSingleton) {
+    sSingleton = new TimeService();
+    ClearOnShutdown(&sSingleton);
+  }
+  nsRefPtr<TimeService> service = sSingleton.get();
+  return service.forget();
+}
+
+NS_IMETHODIMP
+TimeService::Set(int64_t aTimeInMS) {
+  hal::AdjustSystemClock(aTimeInMS - (JS_Now() / PR_USEC_PER_MSEC));
+  return NS_OK;
+}
+
+} // namespace time
+} // namespace dom
+} // namespace mozilla