cairo_font_face_t*
ScaledFontDWrite::GetCairoFontFace()
{
  if (!mFontFace) {
    return nullptr;
  }

  return cairo_dwrite_font_face_create_for_dwrite_fontface(nullptr, mFontFace);
}
cairo_font_face_t *
gfxDWriteFont::CairoFontFace()
{
    if (!mCairoFontFace) {
#ifdef CAIRO_HAS_DWRITE_FONT
        mCairoFontFace = 
            cairo_dwrite_font_face_create_for_dwrite_fontface(
            ((gfxDWriteFontEntry*)mFontEntry.get())->mFont, mFontFace);
#endif
    }
    return mCairoFontFace;
}