Merge StyleSheet into CSSStyleSheet.

sky/engine/core/dom/ShadowTreeStyleSheetCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 32 matching lines @@
 
 void ShadowTreeStyleSheetCollection::collectStyleSheets(StyleEngine* engine, StyleSheetCollection& collection)
 {
     DocumentOrderedList::iterator begin = m_styleSheetCandidateNodes.begin();
     DocumentOrderedList::iterator end = m_styleSheetCandidateNodes.end();
     for (DocumentOrderedList::iterator it = begin; it != end; ++it) {
         Node* node = *it;
         if (!isHTMLStyleElement(*node))
             continue;
 
-        StyleSheet* sheet = toHTMLStyleElement(node)->sheet();
+        CSSStyleSheet* sheet = toHTMLStyleElement(node)->sheet();
         if (sheet)
             collection.appendSheetForList(sheet);
-        if (sheet && sheet->isCSSStyleSheet())
-            collection.appendActiveStyleSheet(toCSSStyleSheet(sheet));
+        if (sheet)
+            collection.appendActiveStyleSheet(sheet);
     }
 }
 
 void ShadowTreeStyleSheetCollection::updateActiveStyleSheets(StyleEngine* engine)
 {
     StyleSheetCollection collection;
     collectStyleSheets(engine, collection);
 
     if (StyleResolver* styleResolver = engine->resolver()) {
         // We should not destroy StyleResolver when we find any stylesheet update in a shadow tree.
         // In this case, we will reset rulesets created from style elements in the shadow tree.
         styleResolver->resetAuthorStyle(treeScope());
         styleResolver->removePendingAuthorStyleSheets(m_activeAuthorStyleSheets);
         styleResolver->lazyAppendAuthorStyleSheets(0, collection.activeAuthorStyleSheets());
     }
 
     toShadowRoot(treeScope().rootNode()).host()->setNeedsStyleRecalc(SubtreeStyleChange);
 
     collection.swap(*this);
     updateUsesRemUnits();
 }
 
 }