Use removeFontFace to avoid resetting fontSelector.

Source/core/css/StyleSheetContents.h

Index: Source/core/css/StyleSheetContents.h
diff --git a/Source/core/css/StyleSheetContents.h b/Source/core/css/StyleSheetContents.h
index 85650d7e59f2d275796a1f5dcbb63dc79880afea..b71d3927c071165c05ea87fee5cb38d1b60fdff6 100644
--- a/Source/core/css/StyleSheetContents.h
+++ b/Source/core/css/StyleSheetContents.h
@@ -41,6 +41,7 @@ class Document;
 class Node;
 class SecurityOrigin;
 class StyleRuleBase;
+class StyleRuleFontFace;
 class StyleRuleImport;
 
 class StyleSheetContents : public RefCountedWillBeRefCountedGarbageCollected<StyleSheetContents> {
@@ -94,6 +95,7 @@ public:
 
     void setHasFontFaceRule(bool b) { m_hasFontFaceRule = b; }
     bool hasFontFaceRule() const { return m_hasFontFaceRule; }
+    void findFontFaceRules(Vector<const StyleRuleFontFace*>& fontFaceRules);
 
     void parserAddNamespace(const AtomicString& prefix, const AtomicString& uri);
     void parserAppendRule(PassRefPtr<StyleRuleBase>);
@@ -156,6 +158,7 @@ public:
 private:
     StyleSheetContents(StyleRuleImport* ownerRule, const String& originalURL, const CSSParserContext&);
     StyleSheetContents(const StyleSheetContents&);
+    void notifyRemoveFontFaceRule(const StyleRuleFontFace*);
 
     void clearCharsetRule();