Introduce FontFamily::hasVariationSelector
This CL introduces new method hasVariationSelector into FontFamily but it
is not used in production code. So no behavior changes are expected.
This CL contains the following changes:
- Introduce hasVariationSelector which returns true if the corresponding
font has a glyph for a code point and variation selector pair.
- Introduce purgeHbFontCache since hb_face_t won't be released by
keeping hb_font_t.
- Introduce unit tests with self-built font.
Change-Id: I659a6d03d9ec446b409e1fba2758452abb9f44fa
10 files changed