Make text visible when font loading takes longer than 3 seconds

Source/platform/fonts/FontData.h

 /*
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 36 matching lines @@
     }
 
     virtual ~FontData();
 
     virtual const SimpleFontData* fontDataForCharacter(UChar32) const = 0;
     virtual bool isCustomFont() const = 0;
     virtual bool isLoading() const = 0;
     // Returns whether this is a temporary font data for a custom font which is not yet loaded.
     virtual bool isLoadingFallback() const = 0;
     virtual bool isSegmented() const = 0;
+    virtual bool shouldSkipDrawing() const = 0;
 
     void setMaxGlyphPageTreeLevel(unsigned level) const { m_maxGlyphPageTreeLevel = level; }
     unsigned maxGlyphPageTreeLevel() const { return m_maxGlyphPageTreeLevel; }
 
 #ifndef NDEBUG
     virtual String description() const = 0;
 #endif
 
 private:
     mutable unsigned m_maxGlyphPageTreeLevel;
 };
 
 } // namespace WebCore
 
 #endif // FontData_h