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

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 907871119681fae46034bb0897fc84f90d9201a9..4f561da624b76710b37673f76e7a720c601bec63 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -222,6 +222,17 @@ void StyleResolver::finishAppendAuthorStyleSheets()
     collectViewportRules();
 }
 
+void StyleResolver::resetFontSelector()
+{
+    ASSERT(m_fontSelector);
+    m_fontSelector->unregisterForInvalidationCallbacks(this);
+    m_fontSelector->clearDocument();
+    invalidateMatchedPropertiesCache();
+
+    m_fontSelector = CSSFontSelector::create(&m_document);
+    m_fontSelector->registerForInvalidationCallbacks(this);
+}
+
 void StyleResolver::resetAuthorStyle(const ContainerNode* scopingNode)
 {
     // FIXME: When chanking scoped attribute, scopingNode's hasScopedHTMLStyleChild has been already modified.