[HTML Imports] Implement "load" and "error" events.

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 47 matching lines @@
     WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassRefPtr<LinkStyle> create(HTMLLinkElement* owner);
 
     explicit LinkStyle(HTMLLinkElement* owner);
     virtual ~LinkStyle();
 
     virtual Type type() const OVERRIDE { return Style; }
     virtual void process() OVERRIDE;
     virtual void ownerRemoved() OVERRIDE;
+    virtual bool hasLoaded() const OVERRIDE { return m_loadedSheet; }
 
     void startLoadingDynamicSheet();
     void notifyLoadedSheetAndAllCriticalSubresources(bool errorOccurred);
     bool sheetLoaded();
 
     void setDisabledState(bool);
     void setSheetTitle(const String&);
 
     bool styleSheetIsLoading() const;
     bool hasSheet() const { return m_sheet; }
-    bool hasLoadedSheet() const { return m_loadedSheet; }
     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 ResourceClient
     virtual void setCSSStyleSheet(const String& href, const KURL& baseURL, const String& charset, const CachedCSSStyleSheet*);
 
@@ skipping 53 matching lines @@
     Document* import() const;
 
     bool styleSheetIsLoading() const;
 
     bool isDisabled() const { return linkStyle() && linkStyle()->isDisabled(); }
     bool isEnabledViaScript() const { return linkStyle() && linkStyle()->isEnabledViaScript(); }
     void setSizes(const String&);
     DOMSettableTokenList* sizes() const;
 
     void dispatchPendingEvent(LinkEventSender*);
+    void scheduleEvent();
     static void dispatchPendingLoadEvents();
 
     // From LinkLoaderClient
     virtual bool shouldLoadLink() OVERRIDE;
 
     // For LinkStyle
     bool loadLink(const String& type, const KURL& url) { return m_linkLoader.loadLink(m_relAttribute, type, url, document()); }
     bool isAlternate() const { return linkStyle()->isUnset() && m_relAttribute.isAlternate(); }
     bool shouldProcessStyle() { return linkResourceToProcess() && linkStyle(); }
 
@@ skipping 43 matching lines @@
 
 inline HTMLLinkElement* toHTMLLinkElement(Node* node)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(HTMLNames::linkTag));
     return static_cast<HTMLLinkElement*>(node);
 }
 
 } //namespace
 
 #endif