Implement FreeType COLR/CPAL support.

FreeType has supported color palette related features and Skia needs to
update its support for these new FreeType APIs.

BUG=skia:8030

Change-Id: Idf7e4477dfeb3481f5f145481c8e33ed219b5b8d
Reviewed-on: https://skia-review.googlesource.com/139763
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Dominik Röttsches <drott@google.com>
Commit-Queue: Bruce Wang <brucewang@google.com>
3 files changed