Implement the Request/Response bits of Background Fetch

third_party/WebKit/Source/modules/background_fetch/BackgroundFetchFailEvent.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 BackgroundFetchFailEvent_h
 #define BackgroundFetchFailEvent_h
 
 #include "modules/background_fetch/BackgroundFetchEvent.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/AtomicString.h"
 
 namespace blink {
 
 class BackgroundFetchFailEventInit;
+class BackgroundFetchSettledRequest;
 
 class BackgroundFetchFailEvent final : public BackgroundFetchEvent {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   static BackgroundFetchFailEvent* create(
       const AtomicString& type,
       const BackgroundFetchFailEventInit& initializer) {
     return new BackgroundFetchFailEvent(type, initializer);
   }
 
   ~BackgroundFetchFailEvent() override;
 
+  // Web Exposed attribute defined in the IDL file.
+  HeapVector<Member<BackgroundFetchSettledRequest>> failedFetches() const;
+
   // ExtendableEvent interface.
   const AtomicString& interfaceName() const override;
 
+  DECLARE_VIRTUAL_TRACE();
+
  private:
   BackgroundFetchFailEvent(const AtomicString& type,
                            const BackgroundFetchFailEventInit&);
+
+  HeapVector<Member<BackgroundFetchSettledRequest>> m_failedFetches;
 };
 
 }  // namespace blink
 
 #endif  // BackgroundFetchFailEvent_h