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 notifyGenericFontFamilyChange() { invalidate(SettingsDelegate::FontFamilyChange); }

[dglazkov, 2014/01/29 05:11:50]

I was hoping to avoid this function altogether. Do we need a VC to talk this
through?

The key thing here is that in production, the genericFontFamilySettings is only
set once, when creating the renderer. There are no sub-systems that enable
changing them, right? Why do we need this complex notification system that
attempts to pretend that this change could happen anytime?

[tasak, 2014/01/29 10:13:43]

Looking at some layout test or WebSettings, GenericFontFamilySettings might be
updated from chrome side via some interface?

I'm not sure. At least, some layout test depends on that
window.internals.settings.setXXXFontFamily can update all existing
GenericFontFamilySettings.
So we can fix (or remove) the layout tests? (e.g.
fast/text/international/content-language-font-selection.html)

 
     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 38 matching lines @@
 
     SETTINGS_MEMBER_VARIABLES
 
     bool m_isScriptEnabled : 1;
     bool m_openGLMultisamplingEnabled : 1;
 };
 
 } // namespace WebCore
 
 #endif // Settings_h