Use removeFontFace to avoid resetting fontSelector.

Source/core/dom/StyleEngine.h

Index: Source/core/dom/StyleEngine.h
diff --git a/Source/core/dom/StyleEngine.h b/Source/core/dom/StyleEngine.h
index 36c4b9d4bbbd48f888c77488994011240bd60e8d..92ec13f1a5d701f96269c908aeac36db11a421da 100644
--- a/Source/core/dom/StyleEngine.h
+++ b/Source/core/dom/StyleEngine.h
@@ -49,6 +49,7 @@ class Node;
 class RuleFeatureSet;
 class ShadowTreeStyleSheetCollection;
 class StyleResolver;
+class StyleRuleFontFace;
 class StyleSheet;
 class StyleSheetCollection;
 class StyleSheetContents;
@@ -164,6 +165,8 @@ public:
     void clearMasterResolver();
 
     CSSFontSelector* fontSelector() { return m_fontSelector.get(); }
+    void removeFontFaceRules(const Vector<const StyleRuleFontFace*>&);
+    // FIXME: still need to use resetFontSelector when GenericFontFamilySettings is changed.
     void resetFontSelector();
 
     void didAttach();