Use removeFontFace to avoid resetting fontSelector.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 6b96c8cf4b7da8f3ced73b2c7ee957bbaac94889..1d8d40bfa62e412836bc7cdf76c43820ac5f6bf4 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -1942,6 +1942,11 @@ void Document::clearStyleResolver()
     m_styleEngine->clearResolver();
 }
 
+CSSFontSelector* Document::fontSelector() const
+{
+    return m_styleEngine->fontSelector();
+}
+
 void Document::attach(const AttachContext& context)
 {
     ASSERT(m_lifecyle.state() == DocumentLifecycle::Inactive);