Blink side of exposing the service worker registration associated with geofencing API calls.

Source/modules/geofencing/WorkerNavigatorGeofencing.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WorkerNavigatorGeofencing_h
 #define WorkerNavigatorGeofencing_h
 
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Geofencing;
 class WorkerNavigator;
 
+// FIXME: Delete this class once ServiceWorkerRegistration is exposed in service workers.
 class WorkerNavigatorGeofencing final : public NoBaseWillBeGarbageCollectedFinalized<WorkerNavigatorGeofencing>, public WillBeHeapSupplement<WorkerNavigator> {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(WorkerNavigatorGeofencing);
     WTF_MAKE_NONCOPYABLE(WorkerNavigatorGeofencing);
 public:
     virtual ~WorkerNavigatorGeofencing();
     static WorkerNavigatorGeofencing& from(WorkerNavigator&);
 
     static Geofencing* geofencing(WorkerNavigator&);
     Geofencing* geofencing();
 
     virtual void trace(Visitor*) override;
 
 private:
     WorkerNavigatorGeofencing();
     static const char* supplementName();
 
     PersistentWillBeMember<Geofencing> m_geofencing;
 };
 
 } // namespace blink
 
 #endif // WorkerNavigatorGeofencing_h