fontSelector should be reset when removing stylesheets which has @font-face rule.

Source/core/dom/DocumentStyleSheetCollection.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 140 matching lines @@
 {
     Vector<RefPtr<StyleSheet> > styleSheets;
     Vector<RefPtr<CSSStyleSheet> > activeCSSStyleSheets;
     activeCSSStyleSheets.append(collections->injectedAuthorStyleSheets());
     activeCSSStyleSheets.append(collections->documentAuthorStyleSheets());
     collectActiveCSSStyleSheetsFromSeamlessParents(activeCSSStyleSheets, document());
     collectStyleSheets(collections, styleSheets, activeCSSStyleSheets);
 
     StyleResolverUpdateType styleResolverUpdateType;
     bool requiresFullStyleRecalc;
-    analyzeStyleSheetChange(updateMode, activeAuthorStyleSheets(), activeCSSStyleSheets, styleResolverUpdateType, requiresFullStyleRecalc);
+    bool requiresResetFontSelector;
+    analyzeStyleSheetChange(updateMode, activeAuthorStyleSheets(), activeCSSStyleSheets, styleResolverUpdateType, requiresFullStyleRecalc, requiresResetFontSelector);
 
     if (styleResolverUpdateType == Reconstruct) {
         document()->clearStyleResolver();
     } else {
         StyleResolver* styleResolver = document()->styleResolverIfExists();
         ASSERT(styleResolver);
         // FIXME: We might have already had styles in child treescope. In this case, we cannot use buildScopedStyleTreeInDocumentOrder.
         // Need to change "false" to some valid condition.
         styleResolver->setBuildScopedStyleTreeInDocumentOrder(false);
         if (styleResolverUpdateType == Reset) {
             resetAllRuleSetsInTreeScope(styleResolver);
+            if (requiresResetFontSelector)
+                styleResolver->resetFontSelector();
             styleResolver->appendAuthorStyleSheets(0, activeCSSStyleSheets);
         } else {
             ASSERT(styleResolverUpdateType == Additive);
             styleResolver->appendAuthorStyleSheets(m_activeAuthorStyleSheets.size(), activeCSSStyleSheets);
         }
     }
     m_scopingNodesForStyleScoped.didRemoveScopingNodes();
     m_activeAuthorStyleSheets.swap(activeCSSStyleSheets);
     m_styleSheetsForStyleSheetList.swap(styleSheets);
     updateUsesRemUnits();
 
     return requiresFullStyleRecalc;
 }
 
 }