Use removeFontFace to avoid resetting fontSelector.

Source/core/dom/TreeScopeStyleSheetCollection.h

 /*
  * 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) 2011 Google Inc. All rights reserved.
  *
@@ skipping 30 matching lines @@
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class ContainerNode;
 class DocumentStyleSheetCollector;
 class StyleEngine;
 class Node;
 class StyleSheetContents;
 class StyleSheetList;
+class StyleRuleFontFace;
 
 class TreeScopeStyleSheetCollection : public StyleSheetCollection {
 public:
     void addStyleSheetCandidateNode(Node*, bool createdByParser);
     void removeStyleSheetCandidateNode(Node*, ContainerNode* scopingNode);
     bool hasStyleSheetCandidateNodes() const { return !m_styleSheetCandidateNodes.isEmpty(); }
 
 
     bool usesRemUnits() const { return m_usesRemUnits; }
 
     DocumentOrderedList& styleSheetCandidateNodes() { return m_styleSheetCandidateNodes; }
     DocumentOrderedList* scopingNodesForStyleScoped() { return m_scopingNodesForStyleScoped.scopingNodes(); }
     ListHashSet<Node*, 4>* scopingNodesRemoved() { return m_scopingNodesForStyleScoped.scopingNodesRemoved(); }
 
     void clearMediaQueryRuleSetStyleSheets();
 
 protected:
     explicit TreeScopeStyleSheetCollection(TreeScope&);
 
     Document& document() const { return m_treeScope.document(); }
 
     enum StyleResolverUpdateType {
         Reconstruct,
         Reset,
-        Additive,
-        ResetStyleResolverAndFontSelector
+        Additive
     };
 
     struct StyleSheetChange {
         StyleResolverUpdateType styleResolverUpdateType;
         bool requiresFullStyleRecalc;
+        Vector<const StyleRuleFontFace*> fontFaceRulesToRemove;
 
         StyleSheetChange()
             : styleResolverUpdateType(Reconstruct)
             , requiresFullStyleRecalc(true) { }
     };
 
     void analyzeStyleSheetChange(StyleResolverUpdateMode, const StyleSheetCollection&, StyleSheetChange&);
     void resetAllRuleSetsInTreeScope(StyleResolver*);
     void updateUsesRemUnits();
 
 private:
     static StyleResolverUpdateType compareStyleSheets(const Vector<RefPtr<CSSStyleSheet> >& oldStyleSheets, const Vector<RefPtr<CSSStyleSheet> >& newStylesheets, Vector<StyleSheetContents*>& addedSheets);
     bool activeLoadingStyleSheetLoaded(const Vector<RefPtr<CSSStyleSheet> >& newStyleSheets);
 
 protected:
     TreeScope& m_treeScope;
     bool m_hadActiveLoadingStylesheet;
     bool m_usesRemUnits;
 
     DocumentOrderedList m_styleSheetCandidateNodes;
     StyleSheetScopingNodeList m_scopingNodesForStyleScoped;
 };
 
 }
 
 #endif