Use removeFontFace to avoid resetting fontSelector.

Source/core/frame/Settings.h

 /*
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 37 matching lines @@
     EditableLinkLiveWhenNotFocused,
     EditableLinkNeverLive
 };
 
 class Settings {
     WTF_MAKE_NONCOPYABLE(Settings); WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<Settings> create();
 
     GenericFontFamilySettings& genericFontFamilySettings() { return m_genericFontFamilySettings; }
+    void setCursiveFontFamily(const AtomicString&, UScriptCode = USCRIPT_COMMON);
+    void setFantasyFontFamily(const AtomicString&, UScriptCode = USCRIPT_COMMON);
+    void setFixedFontFamily(const AtomicString&, UScriptCode = USCRIPT_COMMON);
+    void setPictographFontFamily(const AtomicString&, UScriptCode = USCRIPT_COMMON);
+    void setSansSerifFontFamily(const AtomicString&, UScriptCode = USCRIPT_COMMON);
+    void setSerifFontFamily(const AtomicString&, UScriptCode = USCRIPT_COMMON);
+    void setStandardFontFamily(const AtomicString&, UScriptCode = USCRIPT_COMMON);
 
     void setTextAutosizingEnabled(bool);
     bool textAutosizingEnabled() const;
 
     // Compensates for poor text legibility on mobile devices. This value is
     // multiplied by the font scale factor when performing text autosizing of
     // websites that do not set an explicit viewport description.
     void setDeviceScaleAdjustment(float);
     float deviceScaleAdjustment() const;
 
@@ skipping 17 matching lines @@
     // It could handle "GL", but that seems a bit overly broad.
     void setOpenGLMultisamplingEnabled(bool flag);
     bool openGLMultisamplingEnabled() { return m_openGLMultisamplingEnabled; }
 
     void setDelegate(SettingsDelegate*);
 
 private:
     Settings();
 
     void invalidate(SettingsDelegate::ChangeType);
+    void notifyFontFamilySettingsChanged();
 
     // FIXME: pageOfShame() is a hack for the inspector code:
     // http://crbug.com/327476
     Page* pageOfShame() const;
 
     SettingsDelegate* m_delegate;
 
     GenericFontFamilySettings m_genericFontFamilySettings;
     float m_deviceScaleAdjustment;
     IntSize m_textAutosizingWindowSizeOverride;
     bool m_textAutosizingEnabled : 1;
 
     SETTINGS_MEMBER_VARIABLES
 
     bool m_isScriptEnabled : 1;
     bool m_openGLMultisamplingEnabled : 1;
 };
 
 } // namespace WebCore
 
 #endif // Settings_h