Preload scan external CSS for @import

third_party/WebKit/Source/core/fetch/ImageResource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 105 matching lines @@
 }
 
 void ImageResource::didAddClient(ResourceClient* client)
 {
     DCHECK((m_multipartParser && isLoading()) || !m_data || m_image);
     Resource::didAddClient(client);
 }
 
 void ImageResource::addObserver(ImageResourceObserver* observer)
 {
-    willAddClientOrObserver();
+    willAddClientOrObserver(MarkAsReferenced);
 
     m_observers.add(observer);
 
     if (isCacheValidator())
         return;
 
     // When the response is not multipart, if |m_data| exists, |m_image| must
     // be created. This is assured that |updateImage()| is called when
     // |appendData()| is called.
     //
@@ skipping 457 matching lines @@
     if (response().wasFetchedViaServiceWorker())
         return response().serviceWorkerResponseType() != WebServiceWorkerResponseTypeOpaque;
     if (!getImage()->currentFrameHasSingleSecurityOrigin())
         return false;
     if (passesAccessControlCheck(securityOrigin))
         return true;
     return !securityOrigin->taintsCanvas(response().url());
 }
 
 } // namespace blink