Prefetch @import files from CSS files.

Source/core/html/HTMLLinkElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2008, 2010 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.
@@ skipping 68 matching lines @@
     bool hasSheet() const { return m_sheet; }
     bool isDisabled() const { return m_disabledState == Disabled; }
     bool isEnabledViaScript() const { return m_disabledState == EnabledViaScript; }
     bool isUnset() const { return m_disabledState == Unset; }
 
     CSSStyleSheet* sheet() const { return m_sheet.get(); }
 
 private:
     // From StyleSheetResourceClient
     virtual void setCSSStyleSheet(const String& href, const KURL& baseURL, const String& charset, const CSSStyleSheetResource*) OVERRIDE;
+    virtual void dataReceived(const CSSStyleSheetResource* cachedStyleSheet, const char* data, int length) OVERRIDE;
 
     enum DisabledState {
         Unset,
         EnabledViaScript,
         Disabled
     };
 
     enum PendingSheetType {
         None,
         NonBlocking,
         Blocking
     };
 
     enum RemovePendingSheetNotificationType {
         RemovePendingSheetNotifyImmediately,
         RemovePendingSheetNotifyLater
     };
 
     void clearSheet();
     void addPendingSheet(PendingSheetType);
     void removePendingSheet(RemovePendingSheetNotificationType = RemovePendingSheetNotifyImmediately);
     Document& document();
 
     RefPtr<CSSStyleSheet> m_sheet;
     DisabledState m_disabledState;
     PendingSheetType m_pendingSheetType;
     bool m_loading;
     bool m_firedLoad;
     bool m_loadedSheet;
+    bool m_isPreloadScanning;
 };
 
 
 class HTMLLinkElement FINAL : public HTMLElement, public LinkLoaderClient {
 public:
     static PassRefPtr<HTMLLinkElement> create(Document&, bool createdByParser);
     virtual ~HTMLLinkElement();
 
     KURL href() const;
     const AtomicString& rel() const;
@@ skipping 72 matching lines @@
     LinkRelAttribute m_relAttribute;
 
     bool m_createdByParser;
     bool m_isInShadowTree;
     int m_beforeLoadRecurseCount;
 };
 
 } //namespace
 
 #endif