Preload scan external CSS for @import

third_party/WebKit/Source/core/fetch/StyleSheetResourceClient.h

 /*
  Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
  Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
  Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  Copyright (C) 2011 Google 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
  version 2 of the License, or (at your option) any later version.
 
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Library General Public License for more details.
 
  You should have received a copy of the GNU Library General Public License
  along with this library; see the file COPYING.LIB.  If not, write to
  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  Boston, MA 02110-1301, USA.
 
  This class provides all functionality needed for loading images, style sheets and html
  pages from the web. It has a memory cache for these objects.
  */
 
 #ifndef StyleSheetResourceClient_h
 #define StyleSheetResourceClient_h
 
+#include "core/CoreExport.h"
 #include "core/fetch/ResourceClient.h"
 #include "platform/weborigin/KURL.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 class CSSStyleSheetResource;
 
-class StyleSheetResourceClient : public GarbageCollectedMixin, public ResourceClient {
+class CORE_EXPORT StyleSheetResourceClient : public GarbageCollectedMixin, public ResourceClient {
 public:
     ~StyleSheetResourceClient() override {}
     static bool isExpectedType(ResourceClient* client) { return client->getResourceClientType() == StyleSheetType; }
     ResourceClientType getResourceClientType() const final { return StyleSheetType; }
     virtual void setCSSStyleSheet(const String& /* href */, const KURL& /* baseURL */, const String& /* charset */, const CSSStyleSheetResource*) {}
     virtual void setXSLStyleSheet(const String& /* href */, const KURL& /* baseURL */, const String& /* sheet */) {}
 
+    // This gets called on the very first appendData call for the
+    // CSSStyleSheetResource. Note this is not called for StyleSheetResources
+    // other than CSSStyleSheetResources.
+    virtual void didAppendFirstData(const CSSStyleSheetResource*) {}
+
     DEFINE_INLINE_VIRTUAL_TRACE() {}
 };
 
 } // namespace blink
 
 #endif // StyleSheetResourceClient_h