diff -r 000000000000 -r 6474c204b198 dom/alarm/AlarmHalService.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/alarm/AlarmHalService.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,100 @@
+/* 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 "AlarmHalService.h"
+
+namespace mozilla {
+namespace dom {
+namespace alarm {
+
+using namespace hal;
+
+NS_IMPL_ISUPPORTS(AlarmHalService, nsIAlarmHalService)
+
+void
+AlarmHalService::Init()
+{
+  mAlarmEnabled = RegisterTheOneAlarmObserver(this);
+  if (!mAlarmEnabled) {
+    return;
+  }
+  RegisterSystemTimezoneChangeObserver(this);
+}
+
+/* virtual */ AlarmHalService::~AlarmHalService() 
+{
+  if (mAlarmEnabled) {
+    UnregisterTheOneAlarmObserver();
+    UnregisterSystemTimezoneChangeObserver(this);
+  }
+}
+
+/* static */ StaticRefPtr<AlarmHalService> AlarmHalService::sSingleton;
+
+/* static */ already_AddRefed<AlarmHalService>
+AlarmHalService::GetInstance()
+{
+  if (!sSingleton) {
+    sSingleton = new AlarmHalService();
+    sSingleton->Init(); 
+    ClearOnShutdown(&sSingleton);
+  }
+
+  nsRefPtr<AlarmHalService> service = sSingleton.get();
+  return service.forget();
+}
+
+NS_IMETHODIMP
+AlarmHalService::SetAlarm(int32_t aSeconds, int32_t aNanoseconds, bool* aStatus)
+{
+  if (!mAlarmEnabled) {
+    return NS_ERROR_FAILURE;
+  }
+
+  bool status = hal::SetAlarm(aSeconds, aNanoseconds);
+  if (status) {
+    *aStatus = status;
+    return NS_OK;
+  } else {
+    return NS_ERROR_FAILURE;
+  }
+}
+
+NS_IMETHODIMP
+AlarmHalService::SetAlarmFiredCb(nsIAlarmFiredCb* aAlarmFiredCb)
+{
+  mAlarmFiredCb = aAlarmFiredCb;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AlarmHalService::SetTimezoneChangedCb(nsITimezoneChangedCb* aTimeZoneChangedCb)
+{
+  mTimezoneChangedCb = aTimeZoneChangedCb;
+  return NS_OK;
+}
+
+void
+AlarmHalService::Notify(const void_t& aVoid)
+{
+  if (!mAlarmFiredCb) {
+    return;
+  }
+  mAlarmFiredCb->OnAlarmFired();
+}
+
+void
+AlarmHalService::Notify(
+  const SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo)
+{
+  if (!mTimezoneChangedCb) {
+    return;
+  }
+  mTimezoneChangedCb->OnTimezoneChanged(
+    aSystemTimezoneChangeInfo.newTimezoneOffsetMinutes());
+}
+
+} // alarm
+} // dom
+} // mozilla