[Background Sync] Add sync registration details to onsync event

Source/modules/background_sync/SyncRegistration.h

 // Copyright 2015 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 SyncRegistration_h
 #define SyncRegistration_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "modules/background_sync/SyncRegistrationOptions.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class ServiceWorkerRegistration;
 class ScriptPromiseResolver;
 class ScriptState;
 struct WebSyncRegistration;
 
-class SyncRegistration final : public GarbageCollectedFinalized<SyncRegistration>, public ScriptWrappable {
+class MODULES_EXPORT SyncRegistration final : public GarbageCollectedFinalized<SyncRegistration>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
+    static SyncRegistration* create(const WebSyncRegistration&, ServiceWorkerRegistration*);
     static SyncRegistration* take(ScriptPromiseResolver*, WebSyncRegistration*, ServiceWorkerRegistration*);
     static void dispose(WebSyncRegistration* registrationRaw);
 
     virtual ~SyncRegistration();
 
     bool hasTag() const { return !m_tag.isNull(); }
     String tag() const { return m_tag; }
     void setTag(String value) { m_tag = value; }
 
     ScriptPromise unregister(ScriptState*);
 
     DECLARE_TRACE();
 
 private:
     SyncRegistration(int64_t id, const SyncRegistrationOptions&, ServiceWorkerRegistration*);
 
     int64_t m_id;
     String m_tag;
 
     Member<ServiceWorkerRegistration> m_serviceWorkerRegistration;
 };
 
 } // namespace blink
 
 #endif // SyncRegistration_h