[skottie,skshaper] Plumb an optional SkFontMgr in SkShaper/SkottieShaper

Skottie already takes an optional client fontmgr at load time, but
SkShaper(HB) currently uses the default fontmgr for fallback.

Plumb the Skottie font manager all the way to SkShaper.

This should give clients more control over font fallback, instead of
relying on the default SkFontMgr.

Change-Id: I3df16b3924a68d232573e25f9e526f523fc1dc08
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/230122
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Ben Wagner aka dogben <benjaminwagner@google.com>
10 files changed