Hide PingLoader lifetime implementation detail from outside view.

third_party/WebKit/Source/core/loader/PingLoader.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 39 matching lines @@
 
 // Issue an asynchronous, one-directional request at some resources, ignoring
 // any response. The request is made independent of any LocalFrame staying alive,
 // and must only stay alive until the transmission has completed successfully
 // (or not -- errors are not propagated back either.) Upon transmission, the
 // the load is cancelled and the loader cancels itself.
 //
 // The ping loader is used by audit pings, beacon transmissions and image loads
 // during page unloading.
 //
-class CORE_EXPORT PingLoader : public RefCountedGarbageCollected<PingLoader>, public LocalFrameLifecycleObserver, private WebURLLoaderClient {
+class CORE_EXPORT PingLoader : public GarbageCollectedFinalized<PingLoader>, public LocalFrameLifecycleObserver, private WebURLLoaderClient {
     USING_GARBAGE_COLLECTED_MIXIN(PingLoader);
     WTF_MAKE_NONCOPYABLE(PingLoader);
 public:
     ~PingLoader() override;
 
     enum ViolationReportType {
         ContentSecurityPolicyViolationReport,
         XSSAuditorViolationReport
     };
 
@@ skipping 20 matching lines @@
     void didFail(WebURLLoader*, const WebURLError&) final;
 
     void timeout(Timer<PingLoader>*);
 
     void didFailLoading(LocalFrame*);
 
     OwnPtr<WebURLLoader> m_loader;
     Timer<PingLoader> m_timeout;
     String m_url;
     unsigned long m_identifier;
+    SelfKeepAlive<PingLoader> m_keepAlive;
 };
 
 } // namespace blink
 
 #endif // PingLoader_h