Fix crash in CSSStyleSheetResource::appendData

third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.cpp

 /*
  * Copyright (C) 2013 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 29 matching lines @@
 }
 
 HTMLResourcePreloader* HTMLResourcePreloader::create(Document& document)
 {
     return new HTMLResourcePreloader(document);
 }
 
 DEFINE_TRACE(HTMLResourcePreloader)
 {
     visitor->trace(m_document);
+    visitor->trace(m_cssPreloaders);
 }
 
 int HTMLResourcePreloader::countPreloads()
 {
     if (m_document->loader())
         return m_document->loader()->fetcher()->countPreloads();
     return 0;
 }
 
 static void preconnectHost(PreloadRequest* request, const NetworkHintsInterface& networkHintsInterface)
@@ skipping 18 matching lines @@
     FetchRequest request = preload->resourceRequest(m_document);
     // TODO(dgozman): This check should go to HTMLPreloadScanner, but this requires
     // making Document::completeURLWithOverride logic to be statically accessible.
     if (request.url().protocolIsData())
         return;
     if (preload->resourceType() == Resource::Script || preload->resourceType() == Resource::CSSStyleSheet || preload->resourceType() == Resource::ImportResource)
         request.setCharset(preload->charset().isEmpty() ? m_document->characterSet().getString() : preload->charset());
     request.setForPreload(true);
     Resource* resource = m_document->loader()->startPreload(preload->resourceType(), request);
     if (resource && preload->resourceType() == Resource::CSSStyleSheet && RuntimeEnabledFeatures::cssPreloadImportEnabled()) {
-        OwnPtr<CSSPreloaderResourceClient> client = adoptPtr(new CSSPreloaderResourceClient(resource, this));
-        resource->addClient(client.get());
-        m_cssPreloaders.add(client.release());
+        m_cssPreloaders.append(new CSSPreloaderResourceClient(resource, this));
     }
 }
 
 } // namespace blink