Use FreeType for OpenType Variations on CoreText < 10.12

third_party/WebKit/Source/platform/fonts/FontPlatformData.h

 /*
  * Copyright (c) 2006, 2007, 2008, Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 92 matching lines @@
 #endif
   FontPlatformData(sk_sp<SkTypeface>,
                    const char* name,
                    float text_size,
                    bool synthetic_bold,
                    bool synthetic_italic,
                    FontOrientation = FontOrientation::kHorizontal);
   ~FontPlatformData();
 
 #if OS(MACOSX)
+  // These methods return a nullptr for FreeType backed SkTypefaces, compare
+  // FontCustomPlatformData, which are used for variable fonts on Mac OS <
+  // 10.12. They should not return nullptr otherwise. So they allow
+  // distinguishing which backend the SkTypeface is using.
   CTFontRef CtFont() const;
   CGFontRef CgFont() const;
 #endif
 
   String FontFamilyName() const;
   float size() const { return text_size_; }
   bool SyntheticBold() const { return synthetic_bold_; }
   bool SyntheticItalic() const { return synthetic_italic_; }
 
   SkTypeface* Typeface() const;
@@ skipping 61 matching lines @@
   mutable RefPtr<HarfBuzzFace> harf_buzz_face_;
   bool is_hash_table_deleted_value_;
 #if OS(WIN)
   int paint_text_flags_;
 #endif
 };
 
 }  // namespace blink
 
 #endif  // ifdef FontPlatformData_h