Removing Nullable<unsigned long> for PeriodicSyncRegistration::m_minPeriod

Source/modules/background_sync/PeriodicSyncRegistration.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 PeriodicSyncRegistration_h
 #define PeriodicSyncRegistration_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "modules/background_sync/PeriodicSyncRegistrationOptions.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class ServiceWorkerRegistration;
 class ScriptPromiseResolver;
 class ScriptState;
 struct WebSyncRegistration;
 
 class PeriodicSyncRegistration final : public GarbageCollectedFinalized<PeriodicSyncRegistration>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PeriodicSyncRegistration* take(ScriptPromiseResolver*, WebSyncRegistration*, ServiceWorkerRegistration*);
     static void dispose(WebSyncRegistration* registrationRaw);
 
     virtual ~PeriodicSyncRegistration();
 
-    bool hasMinPeriod() const { return !m_minPeriod.isNull(); }
-    unsigned long minPeriod() const { return m_minPeriod.get(); }
+    unsigned long minPeriod() const { return m_minPeriod; }
     void setMinPeriod(unsigned long value) { m_minPeriod = value; }
 
-    bool hasNetworkState() const { return !m_networkState.isNull(); }
     String networkState() const { return m_networkState; }
     void setNetworkState(String value) { m_networkState = value; }
 
-    bool hasPowerState() const { return !m_powerState.isNull(); }
     String powerState() const { return m_powerState; }
     void setPowerState(String value) { m_powerState = value; }
 
-    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:
     PeriodicSyncRegistration(int64_t id, const PeriodicSyncRegistrationOptions&, ServiceWorkerRegistration*);
 
     int64_t m_id;
-    Nullable<unsigned long> m_minPeriod;
+    unsigned long m_minPeriod;
     String m_networkState;
     String m_powerState;
     String m_tag;
 
     Member<ServiceWorkerRegistration> m_serviceWorkerRegistration;
 };
 
 } // namespace blink
 
 #endif // PeriodicSyncRegistration_h