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 6dfb08aa3c2c651ec64586430ac7b64ccfcab7cf..4f16f96e3e9582e4a14c0b081a98be7bf78bcedf 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -249,6 +249,17 @@ void StyleResolver::processScopedRules(const RuleSet& authorRules, const KURL& s
     }
 }
 
+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.