Use unicode-range to prevent unnecessary @font-face donwnloads

Source/core/platform/graphics/SegmentedFontData.h

 /*
  * Copyright (C) 2008, 2009 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 62 matching lines @@
 
     virtual bool isCustomFont() const;
     virtual bool isLoading() const;
     virtual bool isSegmented() const;
 
     bool containsCharacter(UChar32) const;
 
     Vector<FontDataRange, 1> m_ranges;
 };
 
+inline SegmentedFontData* toSegmentedFontData(FontData* fontData)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!fontData || fontData->isSegmented());
+    return static_cast<SegmentedFontData*>(fontData);
+}
+
 } // namespace WebCore
 
 #endif // SegmentedFontData_h