Make CSSPreloaderResourceClient hold weak references to its resource

third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 83 matching lines @@
   // Below members only non-null during scan()
   PreloadRequestStream* m_requests = nullptr;
   const KURL* m_predictedBaseElementURL = nullptr;
 };
 
 // Each CSSPreloaderResourceClient keeps track of a single CSS resource, and
 // drives a CSSPreloadScanner as raw data arrives for it. This lets us preload
 // @import tags before parsing.
 class CORE_EXPORT CSSPreloaderResourceClient
     : public GarbageCollectedFinalized<CSSPreloaderResourceClient>,
-      public ResourceOwner<CSSStyleSheetResource, StyleSheetResourceClient> {
+      public StyleSheetResourceClient {
   USING_GARBAGE_COLLECTED_MIXIN(CSSPreloaderResourceClient);
 
  public:
   CSSPreloaderResourceClient(Resource*, HTMLResourcePreloader*);
   ~CSSPreloaderResourceClient();
   void setCSSStyleSheet(const String& href,
                         const KURL& baseURL,
                         const String& charset,
                         const CSSStyleSheetResource*) override;
   void didAppendFirstData(const CSSStyleSheetResource*) override;
   String debugName() const override { return "CSSPreloaderResourceClient"; }
 
   DECLARE_TRACE();
 
  protected:
   // Protected for tests, which don't want to initialize a fully featured
   // DocumentLoader.
   virtual void fetchPreloads(PreloadRequestStream& preloads);
 
  private:
   void scanCSS(const CSSStyleSheetResource*);
+  void clearResource();
 
   enum PreloadPolicy {
     ScanOnly,
     ScanAndPreload,
   };
 
   const PreloadPolicy m_policy;
   WeakMember<HTMLResourcePreloader> m_preloader;
+  WeakMember<CSSStyleSheetResource> m_resource;
 };
 
 }  // namespace blink
 
 #endif