Implement BackgroundFetchManager.fetch() and struct traits

third_party/WebKit/Source/modules/background_fetch/BackgroundFetchRegistration.h

 // Copyright 2017 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 BackgroundFetchRegistration_h
 #define BackgroundFetchRegistration_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "platform/heap/GarbageCollected.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class IconDefinition;
 class ServiceWorkerRegistration;
 
 // Represents an individual Background Fetch registration. Gives developers
 // access to its properties, options, and enables them to abort the fetch.
 class BackgroundFetchRegistration final
     : public GarbageCollectedFinalized<BackgroundFetchRegistration>,
       public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
-  BackgroundFetchRegistration(ServiceWorkerRegistration*,
-                              String tag,
+  BackgroundFetchRegistration(String tag,
                               HeapVector<IconDefinition> icons,
                               long long totalDownloadSize,
                               String title);
   ~BackgroundFetchRegistration();
 
+  // Sets the ServiceWorkerRegistration that this BackgroundFetchRegistration
+  // has been associated with.
+  void setServiceWorkerRegistration(ServiceWorkerRegistration*);
+
   String tag() const;
   HeapVector<IconDefinition> icons() const;
   long long totalDownloadSize() const;
   String title() const;
 
   void abort();
 
   DECLARE_TRACE();
 
  private:
   Member<ServiceWorkerRegistration> m_registration;
 
   String m_tag;
   HeapVector<IconDefinition> m_icons;
   long long m_totalDownloadSize;
   String m_title;
 };
 
 }  // namespace blink
 
 #endif  // BackgroundFetchRegistration_h