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 1e60754d36d15ddc0fbcf509b857f5b323b46c9f..fc5d48abd23a7fdf6d05c0e2a95fdf400a39dadc 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -1986,6 +1986,11 @@ 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);